Set any of the following options in the Property inspector:
Checked Value sets the value to be sent to the server when the radio button is selected. For example, you might type skiing in the CheckedValue text box to indicate a user chose skiing.
Initial State determines whether the radio button is selected or not when the form loads in the browser.
Dynamic lets the server dynamically determine the initial state of the radio button. For example, you can use radio buttons to visually present information stored in a database record. At design time, you dont know that information. At runtime the server reads the database record and checks the radio button if the value matches one you specified.
Class lets you apply CSS rules to the object.