Hi,
try this code
if (!IsPostBack)
{
RadioButton rdn = new RadioButton();
rdn.ID = "rdbtn";
rdn.Text = "ghgfh";
contdiv.Controls.Add(rdn);
}
Control d = contdiv.FindControl("rdbtn");
In the above code,you've to use table id for searching radio button control.
instead of contdiv you've to place your table id
All the Best