Hi rani,

Check this example. Now please take its reference and correct your code.

Database

For this example I have used of Northwind database that you can download using the link given below.

Download Northwind Database

Namespaces

using System.Collections.Generic;
using System.Configuration;
using System.Data;
using System.Data.SqlClient;

Controller

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

    [HttpPost]
    public JsonResult AjaxMethod()
    {
        string query = "SELECT ShipCity, COUNT(orderid) TotalOrders";
        query += " FROM Orders WHERE ShipCountry = 'USA' GROUP BY ShipCity";
        string constr = ConfigurationManager.ConnectionStrings["constr"].ConnectionString;
        List<object> chartData = new List<object>();
        chartData.Add(new object[] { "ShipCity", "TotalOrders" });
        using (SqlConnection con = new SqlConnection(constr))
        {
            using (SqlCommand cmd = new SqlCommand(query))
            {
                cmd.CommandType = CommandType.Text;
                cmd.Connection = con;
                con.Open();
                using (SqlDataReader sdr = cmd.ExecuteReader())
                {
                    while (sdr.Read())
                    {
                        chartData.Add(new object[] { sdr["ShipCity"], sdr["TotalOrders"] });
                    }
                }

                con.Close();
            }
        }

        return Json(chartData);
    }
}

View

<div ng-app="MyApp" ng-controller="MyController">
    <div id="chart" style="width: 500px; height: 400px;">
    </div>
</div>
<script type="text/javascript" src="http://ajax.googleapis.com/ajax/libs/jquery/1.8.3/jquery.min.js"></script>
<script type="text/javascript" src="https://www.gstatic.com/charts/loader.js"></script>
<script type="text/javascript" src="https://code.angularjs.org/1.3.0/angular.js"></script>
<script type="text/javascript">
    var app = angular.module('MyApp', [])
    app.controller('MyController', function ($scope, $http) {
        google.charts.load('current', { 'packages': ['corechart'] });
        google.charts.setOnLoadCallback(function () {
            $http.post("Home/AjaxMethod", { headers: { 'Content-Type': 'application/json'} })
            .then(function (r) {
                var data = google.visualization.arrayToDataTable(r.data);
                var options = {
                    title: 'USA City Distribution',
                    is3D: true
                };
                var chart = new google.visualization.PieChart($("#chart")[0]);
                chart.draw(data, options);
            }, function (response) {
                $window.alert(response.responseText);
            });
        });
    });       
</script>

Screenshot