Hi VasuDev,

Refer below sample and link -

Step by Step Tutorial for performing Insert Edit Update and Delete in GridView in ASP.Net

HTML

<asp:GridView ID="dgCptResult" runat="server" AutoGenerateColumns="False" OnRowEditing="dgCptResult_RowEditing"
    OnPageIndexChanging="dgCptResult_PageIndexChanging1" AllowPaging="True" OnRowCancelingEdit="dgCptResult_RowCancelingEdit1"
    OnRowUpdating="dgCptResult_RowUpdating1" DataKeyNames="HQPHTBSYSID" AutoGenerateEditButton="True">
    <Columns>
        <asp:BoundField DataField="HQPHTBSYSID" HeaderText="HQPID" ReadOnly="True" />
        <asp:BoundField DataField="NAME" HeaderText="NAME" ReadOnly="True" />
        <asp:TemplateField HeaderText="CORRECT">
            <EditItemTemplate>
                <asp:TextBox ID="txtcorrect" runat="server"></asp:TextBox>
            </EditItemTemplate>
            <ItemTemplate>
                <asp:Label ID="lblcorrect" runat="server"></asp:Label>
            </ItemTemplate>
        </asp:TemplateField>
        <asp:TemplateField HeaderText="INCORRECT">
            <EditItemTemplate>
                <asp:TextBox ID="txtincorrect" runat="server"></asp:TextBox>
            </EditItemTemplate>
            <ItemTemplate>
                <asp:Label ID="lblincorrect" runat="server"></asp:Label>
            </ItemTemplate>
        </asp:TemplateField>
        <asp:TemplateField HeaderText="ATTENDED">
            <EditItemTemplate>
                <asp:TextBox ID="txtAtended" runat="server"></asp:TextBox>
            </EditItemTemplate>
            <ItemTemplate>
                <asp:Label ID="lblAtended" runat="server"></asp:Label>
            </ItemTemplate>
        </asp:TemplateField>
        <asp:TemplateField HeaderText="UNATTENDED">
            <EditItemTemplate>
                <asp:TextBox ID="txtUnAtended" runat="server"></asp:TextBox>
            </EditItemTemplate>
            <ItemTemplate>
                <asp:Label ID="lblUnAtended" runat="server"></asp:Label>
            </ItemTemplate>
        </asp:TemplateField>
        <asp:TemplateField HeaderText="RESULT">
            <EditItemTemplate>
                <asp:TextBox ID="txtresult" runat="server"></asp:TextBox>
            </EditItemTemplate>
            <ItemTemplate>
                <asp:Label ID="lblresult" runat="server"></asp:Label>
            </ItemTemplate>
        </asp:TemplateField>
    </Columns>
    <HeaderStyle BackColor="#C0C0FF" />
</asp:GridView>

Namespaces

C#

using System.Data;

VB.Net

Imports System.Data

Code

C#

protected void Page_Load(object sender, EventArgs e)
{
    if (!this.IsPostBack)
    {
        BindGrid();
    }
}

private void BindGrid()
{
    DataTable dt = new DataTable();
    dt.Columns.AddRange(new DataColumn[] { 
                        new DataColumn("HQPHTBSYSID", typeof(int)),
                        new DataColumn("NAME", typeof(string)) });
    dt.Rows.Add(1, "Mudassar Khan");
    dt.Rows.Add(2, "John Hammond");
    dgCptResult.DataSource = dt;
    dgCptResult.DataBind();
}

protected void dgCptResult_PageIndexChanging1(object sender, GridViewPageEventArgs e)
{
    dgCptResult.PageIndex = e.NewPageIndex;
    dgCptResult.DataBind();
}

protected void dgCptResult_RowCancelingEdit1(object sender, GridViewCancelEditEventArgs e)
{
    dgCptResult.EditIndex = -1;
    this.BindGrid();
}

protected void dgCptResult_RowEditing(object sender, GridViewEditEventArgs e)
{
    dgCptResult.EditIndex = e.NewEditIndex;
    this.BindGrid();
}

protected void dgCptResult_RowUpdating1(object sender, GridViewUpdateEventArgs e)
{
    GridViewRow row = dgCptResult.Rows[e.RowIndex];
    int Id = Convert.ToInt32(dgCptResult.DataKeys[e.RowIndex].Values[0]);
    int correct = (Convert.ToInt32((row.FindControl("txtcorrect") as TextBox).Text));
    int inCorrect = (Convert.ToInt32((row.FindControl("txtincorrect") as TextBox).Text));
    int attend = (Convert.ToInt32((row.FindControl("txtAtended") as TextBox).Text));
    int unatttend = (Convert.ToInt32((row.FindControl("txtUnAtended") as TextBox).Text));
    int total = attend + unatttend;
    int result = (correct * 100) / total;
    (row.FindControl("txtresult") as TextBox).Text = result.ToString() + "%";
}

VB.Net

Protected Sub Page_Load(ByVal sender As Object, ByVal e As EventArgs) Handles Me.Load
    If Not Me.IsPostBack Then
        BindGrid()
    End If
End Sub

Private Sub BindGrid()
    Dim dt As DataTable = New DataTable()
    dt.Columns.AddRange(New DataColumn() {New DataColumn("HQPHTBSYSID", GetType(Integer)), New DataColumn("NAME", GetType(String))})
    dt.Rows.Add(1, "Mudassar Khan")
    dt.Rows.Add(2, "John Hammond")
    dgCptResult.DataSource = dt
    dgCptResult.DataBind()
End Sub

Protected Sub dgCptResult_PageIndexChanging1(ByVal sender As Object, ByVal e As GridViewPageEventArgs)
    dgCptResult.PageIndex = e.NewPageIndex
    dgCptResult.DataBind()
End Sub

Protected Sub dgCptResult_RowCancelingEdit1(ByVal sender As Object, ByVal e As GridViewCancelEditEventArgs)
    dgCptResult.EditIndex = -1
    Me.BindGrid()
End Sub

Protected Sub dgCptResult_RowEditing(ByVal sender As Object, ByVal e As GridViewEditEventArgs)
    dgCptResult.EditIndex = e.NewEditIndex
    Me.BindGrid()
End Sub

Protected Sub dgCptResult_RowUpdating1(ByVal sender As Object, ByVal e As GridViewUpdateEventArgs)
    Dim row As GridViewRow = dgCptResult.Rows(e.RowIndex)
    Dim Id As Integer = Convert.ToInt32(dgCptResult.DataKeys(e.RowIndex).Values(0))
    Dim correct As Integer = (Convert.ToInt32((TryCast(row.FindControl("txtcorrect"), TextBox)).Text))
    Dim inCorrect As Integer = (Convert.ToInt32((TryCast(row.FindControl("txtincorrect"), TextBox)).Text))
    Dim attend As Integer = (Convert.ToInt32((TryCast(row.FindControl("txtAtended"), TextBox)).Text))
    Dim unatttend As Integer = (Convert.ToInt32((TryCast(row.FindControl("txtUnAtended"), TextBox)).Text))
    Dim total As Integer = attend + unatttend
    Dim result As Integer = (correct * 100) / total
    TryCast(row.FindControl("txtresult"), TextBox).Text = result.ToString() & "%"
End Sub

Screenshot