Their can be multiple issues with your code.
Few which I can see are as below.
1) Delcare object of
RadioButtonList
as below.
RadioButtonList r = new RadioButtonList();
2) Use below syntax while adding
Items
.
r.Items.Add(dt.Rows[ctr]["choice1"].ToString());
Also debug your code and check your
dt
is not
null
and has Rows in it.