I found the solution for my requirement.
protected void present_CheckedChanged(object sender, EventArgs e)
{
RadioButton button = sender as RadioButton;
GridViewRow row = button.NamingContainer as GridViewRow;
RadioButton pres_button = row.FindControl("present") as RadioButton;
}
Using this code, we can access the elements in the template field of a gridview. Firstly we have to get the sender object as any element required. Then create an Gridviewrow object to access the row required. After that you can access any element in the Gridview using the syntax
ElementType element_name=row.FindControl("elementID_given_in_aspx_page") as ElementType;
as an example,
RadioButton pres_button = row.FindControl("present") as RadioButton;
This solution is working fine for me. I hope it'll be useful to all.
Thanks