for that you need to put a place holder hidden & then add control to that.
<asp:PlaceHolder ID="PlaceHolder1" runat="server">
</asp:PlaceHolder>
& Then add code on button click
protected void btn0_Click(object sender, EventArgs e)
{
Label myLabel = new Label();
myLabel.Text = "Sample Label";
Panel Panel1 = new Panel();
Panel1.Controls.Add(myLabel);
PlaceHolder1.Controls.Add(Panel1);
RadioButton rd = new RadioButton();
rd.Checked = true;
Panel1.Controls.Add(rd);
}