RadioButtonList are used when we need to make multiple sets of choices available, but we want the user to select only one of them. If they click on a second selection after making a first, the first selection is removed.

RadioButtonList also supports data binding.

<asp:RadioButtonList ID="RadioButtonList1" runat="server">
 <asp:ListItem>c#</asp:ListItem>
 <asp:ListItem>j#</asp:ListItem>
 <asp:ListItem>vb</asp:ListItem>
 <asp:ListItem>c++</asp:ListItem>
 <asp:ListItem>c</asp:ListItem>
</asp:RadioButtonList>

RadioButtonList event

The default event of the RadioButtonList is the SelectedIndexChanged

<asp:RadioButtonList ID="RadioButtonList1" runat="server" AutoPostBack="True" 
        Font-Bold="True" Font-Italic="True" Font-Names="Arial" ForeColor="Red" 
       onselectedindexchanged="RadioButtonList1_SelectedIndexChanged">
       <asp:ListItem>c#</asp:ListItem>
       <asp:ListItem>j#</asp:ListItem>
       <asp:ListItem>vb</asp:ListItem>
       <asp:ListItem>c++</asp:ListItem>
       <asp:ListItem>c</asp:ListItem>
</asp:RadioButtonList>
protected void RadioButtonList1_SelectedIndexChanged (object sender,  EventArgs e)
    {
         Label1.Text = RadioButtonList1.SelectedItem.Text;
    }

When you select any option then SelectedIndexChanged event will fire and it will show the selected value in Label.

We can change RadioButton appearance

<asp:RadioButtonList ID="RadioButtonList1" runat="server" Font-Bold="True" 
         Font-Italic="True" Font-Names="Arial" ForeColor="Red" 
         onselectedindexchanged="RadioButtonList1_SelectedIndexChanged">
         <asp:ListItem>c#</asp:ListItem>
         <asp:ListItem>j#</asp:ListItem>
         <asp:ListItem>vb</asp:ListItem>
         <asp:ListItem>c++</asp:ListItem>
         <asp:ListItem>c</asp:ListItem>
</asp:RadioButtonList>