Hi  suryadevara66,
Inorder to scroll using mouse you need to make use of mousemove event handler.
Inside the mousemove event handler, you need to set the scrollLeft property.
Database
For this example I have used of Northwind database that you can download using the link given below.
Download Northwind Database
HTML
The following HTML Markup consists of a Div.
The Div has been set with overflow: hidden to apply scrollbar.
The Div consists of a GridView to which the AllowPaging property is set to True and OnPageIndexChanging event handler is assigned.
<div id="dvContents" style="border: 1px solid #ccc; width: 500px; overflow: hidden;">
    <asp:GridView ID="gvCustomers" runat="server" AllowPaging="true" OnPageIndexChanging="OnPageIndexChanging">
    </asp:GridView>
</div>
<script type="text/javascript" src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.7.1/jquery.min.js"></script>
<script type="text/javascript">
    $(function () {
        var down = false;
        var scrollLeft = 0;
        var x = 0;
        // Adding mousedown event.
        $('#dvContents').mousedown(function (e) {
            // mousedown is set to True.
            down = true;
            // scrollLeft is set.
            scrollLeft = this.scrollLeft;
            x = e.clientX;
        }).mouseup(function () { // Adding mouseup event.
            // mousedown is set to False.
            down = false;
        }).mousemove(function (e) {
            if (down) {
                // scrollLeft is calculated.
                this.scrollLeft = scrollLeft + x - e.clientX;
            }
        }).mouseleave(function () { // Adding mouseleave event.
            // mousedown is set to False.
            down = false;
        });
    });
</script>
Namespaces
You need to inherit the following namespaces.
C#
using System.Data;
using System.Data.SqlClient;
using System.Configuration;
VB.Net
Imports System.Data
Imports System.Data.SqlClient
Imports System.Configuration
Code
The GridView has been populated with data from Customers table of Northwind Database.
C#
protected void Page_Load(object sender, EventArgs e)
{
    if (!this.IsPostBack)
    {
        this.BindGridView();
    }
}
private void BindGridView()
{
    string constr = ConfigurationManager.ConnectionStrings["constr"].ConnectionString;
    string query = "SELECT * FROM Customers;";
    using (SqlConnection con = new SqlConnection(constr))
    {
        using (SqlDataAdapter sda = new SqlDataAdapter(query, con))
        {
            using (DataTable dt = new DataTable())
            {
                sda.Fill(dt);
                gvCustomers.DataSource = dt;
                gvCustomers.DataBind();
            }
        }
    }
}
protected void OnPageIndexChanging(object sender, GridViewPageEventArgs e)
{
    gvCustomers.PageIndex = e.NewPageIndex;
    this.BindGridView();
}
VB.Net
Protected Sub Page_Load(sender As Object, e As EventArgs) Handles Me.Load
    If Not Me.IsPostBack Then
        Me.BindGridView()
    End If
End Sub
Private Sub BindGridView()
    Dim constr As String = ConfigurationManager.ConnectionStrings("constr").ConnectionString
    Dim query As String = "SELECT * FROM Customers;"
    Using con As SqlConnection = New SqlConnection(constr)
        Using sda As SqlDataAdapter = New SqlDataAdapter(query, con)
            Using dt As DataTable = New DataTable()
                sda.Fill(dt)
                gvCustomers.DataSource = dt
                gvCustomers.DataBind()
            End Using
        End Using
    End Using
End Sub
Protected Sub OnPageIndexChanging(sender As Object, e As GridViewPageEventArgs)
    gvCustomers.PageIndex = e.NewPageIndex
    Me.BindGridView()
End Sub
Screenshot
