I am not sure what you are exactly trying to do. But, here is my sample code and see if this helps and provide more details on what you need.
I would say name each option/radio button in the group box just to have a common char in the Name. So, it would be easy for you to identify while looping.
Private Sub Groups_Load(sender As Object, e As System.EventArgs) Handles Me.Load
Display(Me)
End Sub
Private Sub Display(ByVal parent As Control)
For Each childControl As Control In parent.Controls
Select Case True
Case TypeOf (childControl) Is RadioButton
If childControl.Name.Contains("1") Then
DirectCast(childControl, RadioButton).Checked = True
Else
DirectCast(childControl, RadioButton).Checked = False
End If
Case TypeOf (childControl) Is GroupBox
Display(childControl)
End Select
Next
End Sub