Hi mahesh213,

Check the below code.

Controller

public class HomeController : Controller
{
    // GET: Home
    public ActionResult Index()
    {
        return View();
    }

    [HttpGet]
    public ActionResult GetReportNames()
    {
        TestEntities db = new TestEntities();
        var coun = db.Report1.Select(model => new { model.RId, model.RName }).ToList();
        return Json(coun, JsonRequestBehavior.AllowGet);
    }

    [HttpPost]
    public JsonResult getAll(int Id)
    {
        TestEntities db = new TestEntities();
        List<Details> employeeList = (from E in db.ReportSettings
                                        where E.RId == Id
                                        orderby E.RSId
                                        select new Details
                                        {
                                            RSId = E.RSId,
                                            RId = E.RId,
                                            CName = E.CName,
                                            CType = E.CType,
                                            ValueCName = E.ValueCName,
                                            DisplayCName = E.DisplayCName,
                                            FromTable = E.FromTable,
                                            Date = E.Date
                                        }).ToList();
        foreach (Details details in employeeList)
        {
            if (details.CType.ToLower() == "dropdown")
            {
                var coun = db.ReportSettings.Where(x => x.CType == details.CType && x.RId == details.RId && x.RSId == details.RSId).ToList();
                string fromTable = coun[0].FromTable;
                string displayCName = coun[0].DisplayCName;
                string valueCName = coun[0].ValueCName;
                // Generate dynamic query.
                string query = "SELECT " + displayCName + " AS Text," + valueCName + " AS Value FROM " + fromTable;
                // Execute dynamic query.
                SqlConnection con = new SqlConnection();
                string connectionstring = ConfigurationManager.ConnectionStrings["constr"].ConnectionString;
                con.ConnectionString = connectionstring;
                SqlCommand cmd = new SqlCommand(query, con);
                con.Open();
                SqlDataReader sdr = cmd.ExecuteReader();
                List<SelectListItem> values = new List<SelectListItem>();
                while (sdr.Read())
                {
                    values.Add(new SelectListItem
                    {
                        Text = sdr["Text"].ToString(),
                        Value = sdr["Value"].ToString()
                    });
                }
                con.Close();
                // Adding options for DropDownList.
                details.DDLValues = values;
            }
            else if (details.CType.ToLower() == "datepicker")
            {
                // Settting DatePicker value to display default text.
                switch (details.Date.ToLower())
                {
                    case "today":
                        details.Date = DateTime.Now.ToString("yyyy-MM-dd");
                        break;
                    case "yesterday":
                        details.Date = DateTime.Now.AddDays(-1).ToString("yyyy-MM-dd");
                        break;
                    default:
                        break;
                }
            }
        }

        return Json(employeeList, JsonRequestBehavior.AllowGet);
    }

    [HttpPost]
    public ActionResult PopulateTable(Detail values)
    {
        TestEntities db = new TestEntities();
        // Getting the query from Report1 table.
        string query = db.Report1.Where(x => x.RId == values.RId).Select(x => x.RQuery).FirstOrDefault();
        for (int i = 0; i < values.details.Count; i++)
        {
            string key = "{" + values.details[i].Text + "}";
            string value = "'" + values.details[i].Value + "'";
            // Replace the place holder with value.
            query = query.Replace(key, value);
        }
        // Execute your final query and return DataTable.
        string conString = ConfigurationManager.ConnectionStrings["constr"].ConnectionString;
        SqlCommand cmd = new SqlCommand(query);
        DataTable dt = new DataTable();
        using (SqlConnection con = new SqlConnection(conString))
        {
            using (SqlDataAdapter sda = new SqlDataAdapter())
            {
                cmd.Connection = con;
                sda.SelectCommand = cmd;
                sda.Fill(dt);
            }
        }

        // Generating html table.
        string html = "<table border='1' width='100%'><tr>";
        for (int k = 0; k < dt.Columns.Count; k++)
        {
            html += "<th>" + dt.Columns[k].ColumnName + "</th>";
        }
        html += "</tr>";
        for (int i = 0; i < dt.Rows.Count; i++)
        {
            html += "<tr>";
            for (int k = 0; k < dt.Columns.Count; k++)
            {
                html += "<td>" + dt.Rows[i][k].ToString().Trim() + "</td>";
            }
            html += "</tr>";
        }
        html += "</table>";
        // Converting html table to byte array.
        using (MemoryStream stream = new MemoryStream())
        {
            StringReader sr = new StringReader(html);
            Document pdfDoc = new Document(PageSize.B2, 5f, 5f, 10f, 5f);

            PdfWriter writer = PdfWriter.GetInstance(pdfDoc, stream);
            pdfDoc.Open();
            XMLWorkerHelper.GetInstance().ParseXHtml(writer, pdfDoc, sr);
            pdfDoc.Close();
            // Save byte array in TempData.
            TempData["Data"] = stream.ToArray();
        }
        TempData["FileName"] = "Report.pdf";

        return new JsonResult() { Data = new { FileName = "Report.pdf" } };
    }

    [HttpGet]
    public virtual ActionResult Download()
    {
        if (TempData["Data"] != null)
        {
            // Reading byte array from TempData and download file.
            byte[] data = TempData["Data"] as byte[];
            return File(data, "application/pdf", TempData["FileName"].ToString());
        }
        else
        {
            return new EmptyResult();
        }
    }

    public class Detail
    {
        public int RId { get; set; }
        public List<SelectListItem> details { get; set; }
    }

    public class Details
    {
        public int RSId { get; set; }
        public int? RId { get; set; }
        public string CName { get; set; }
        public string CType { get; set; }
        public string ValueCName { get; set; }
        public string DisplayCName { get; set; }
        public string FromTable { get; set; }
        public string Date { get; set; }
        public List<SelectListItem> DDLValues { get; set; }
    }
}

View

<html xmlns="http://www.w3.org/1999/xhtml">
<head>
    <title>Index</title>
    <link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/twitter-bootstrap/3.3.7/css/bootstrap.min.css" />
    <script type="text/javascript" src="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/js/bootstrap.min.js"></script>
    <script type="text/javascript" src="https://cdnjs.cloudflare.com/ajax/libs/angular.js/1.5.5/angular.js"></script>
    <script type="text/javascript">
        var app = angular.module("MyApp", []);
        app.controller("MyControll", ['$scope', '$http', '$filter', function ($scope, $http, $filter) {
            GetReportName();
            function GetReportName() {
                $scope.reports = [];
                $http({
                    method: 'Get',
                    url: '/Home/GetReportNames'
                }).success(function (data, status, headers, config) {
                    $scope.reports = data;
                }).error(function (data, status, headers, config) {
                    $scope.message = 'Unexpected Error';
                });
            }

            $scope.Change = function () {
                var Id1 = $scope.RName;
                if (Id1 != null) {
                    $http({
                        method: 'POST',
                        url: '/Home/getAll/',
                        params: { Id: Id1 }
                    }).success(function (data, status, headers, config) {
                        for (var i = 0; i < data.length; i++) {
                            if (data[i].Date != null) {
                                data[i].Date = new Date(data[i].Date);
                            }
                        }
                        $scope.items = data;
                    }).error(function (data, status, headers, config) {
                        $scope.items = 'Unexpected Error';
                    });
                }
            }

            function ConvertDate(d) {
                var parts = d.split(" ");
                var months = { Jan: "01", Feb: "02", Mar: "03", Apr: "04", May: "05", Jun: "06", Jul: "07", Aug: "08", Sep: "09", Oct: "10", Nov: "11", Dec: "12" };
                return parts[3] + "/" + months[parts[1]] + "/" + parts[2];
            }
            $scope.Save = function () {
                var Id1 = $scope.items;
                var rId = $scope.RName;
                var details = {};
                var array = [];
                for (var i = 0; i < $scope.items.length; i++) {
                    var data = {};
                    data.Text = $scope.items[i].CName;
                    if ($scope.items[i].CType.toLowerCase() == 'dropdown') {
                        data.Value = $scope.items[i].FromTable;
                    } else if ($scope.items[i].CType.toLowerCase() == 'datepicker') {
                        data.Value = ConvertDate($scope.items[i].Date.toString());
                    } else if ($scope.items[i].CType.toLowerCase() == 'textbox') {
                        data.Value = $scope.items[i].ValueCName;
                    }
                    array.push(data)
                    details.RId = rId;
                    details.details = array;
                }
                $http({
                    method: "Post",
                    url: "/Home/PopulateTable",
                    dataType: 'json',
                    headers: { "Content-Type": "application/json" },
                    data: '{values: ' + JSON.stringify(details) + '}'
                }).success(function (data) {
                    // Redirecting to download file.
                    window.location = '/Home/Download';
                }).error(function (err) {
                })
            }
        } ]);
    </script>
</head>
<body ng-app="MyApp" ng-controller="MyControll">
    <div class="container">
        <div id="wrapper" class="clearfix">
            <form name="userForm" novalidate>
                <h4 class="modal-title" style="text-align: center;">
                    Report Details
                </h4>
                <div class="form-horizontal">
                    <div class="form-row">
                        <div class="col-md-4">
                            <label for="RName">
                                ReportName
                            </label>
                            <select class="form-control" id="RName" select2="" ng-model="RName" containercssclass="all"
                                    ng-options="c.RId as c.RName for c in reports" ng-disabled="disabled" ng-change="Change()">
                                <option value="">Select Name</option>
                            </select>
                        </div>
                    </div>
                </div>
            </form>
        </div>
        <br />
        <div class="well">
            <div ng-repeat="report in items">
                <div class="row">
                    <div class="col-md-2">
                        <label for="RNo">
                            {{report.CName}}
                        </label>
                    </div>
                    <div class="col-md-3" id="dvDynamic">
                        <%--Dynamic Controls display based on CType Start--%>
                        <select class="form-control" ng-model="report.FromTable" ng-show="report.CType.toLowerCase()=='dropdown'"
                                ng-options="c.Text as c.Text for c in report.DDLValues">
                            <option value="">Select</option>
                        </select>
                        <input type="date" class="form-control" ng-model="report.Date" ng-show="report.CType.toLowerCase()=='datepicker'" />
                        <input type="text" class="form-control" ng-model="report.ValueCName" ng-show="report.CType.toLowerCase()=='textbox'" />
                        <%--Dynamic Controls display based on CType End--%>
                    </div>
                </div>
            </div>
            <input type="button" value="Save" ng-click="Save()" />
        </div>
    </div>
</body>
</html>