Hi shardul,

I have created sample. Here you can only edit Name,Address field.

For update refer the below link.

SqlBulkCopy- Bulk Insert records and Update existing rows if record exists using C# and VB.Net

HTML

<div>
    <asp:GridView ID="GridView1" runat="server" AutoGenerateColumns="False">
        <Columns>
            <asp:TemplateField HeaderText="Id">
                <ItemTemplate>
                    <asp:Label ID="lblId" runat="server" Text='<%# Eval("Id") %>'></asp:Label>
                </ItemTemplate>
            </asp:TemplateField>
            <asp:TemplateField HeaderText="Name">
                <ItemTemplate>
                    <asp:Label ID="lblName" runat="server" Text='<%# Eval("Name") %>'></asp:Label>
                    <asp:TextBox ID="txtName" runat="server" Text='<%# Eval("Name") %>' CssClass="hide"></asp:TextBox>
                </ItemTemplate>
            </asp:TemplateField>
            <asp:TemplateField HeaderText="Address">
                <ItemTemplate>
                    <asp:Label ID="lblAddress" runat="server" Text='<%# Eval("Address") %>'></asp:Label>
                    <asp:TextBox ID="txtAddress" runat="server" Text='<%# Eval("Address") %>' CssClass="hide"></asp:TextBox>
                </ItemTemplate>
            </asp:TemplateField>
        </Columns>
    </asp:GridView>
    <br />
    <asp:Button Text="Update" runat="server" OnClick="Update" />
</div>
<div>
    <style type="text/css">
        .hide
        {
            display: none;
        }
    </style>
    <script type="text/javascript" src="http://ajax.googleapis.com/ajax/libs/jquery/1.8.3/jquery.min.js"></script>
    <script type="text/javascript">
        $(function () {
            $('[id*=GridView1] tr td').on('click', function () {
                $('[id*=GridView1] tr td').each(function () {
                    $(this).find('span').show();
                    $(this).find('input[type=text]').hide();
                });
                var val = $(this).find('span').html();
                $(this).find('span').hide();
                $(this).find('input[type=text]').val(val);
                $(this).find('input[type=text]').show();
                $(this).find('input[type=text]').focus();
            });
        });
    </script>
</div>

Code

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

protected void Update(object sender, EventArgs e)
{
    // code for update the record.
}

private void BindGrid()
{
    DataTable dt = new DataTable();
    dt.Columns.AddRange(new DataColumn[3]
    {
        new DataColumn("Id"),
        new DataColumn("Name"),
        new DataColumn("Address")
    });
    dt.Rows.Add(1, "John Hammond", "United States");
    dt.Rows.Add(2, "Mudassar Khan", "India");
    dt.Rows.Add(3, "Suzanne Mathews", "France");
    dt.Rows.Add(4, "Robert Schidner", "Russia");
    this.GridView1.DataSource = dt;
    this.GridView1.DataBind();
}

Screenshot