Hi Prakash,
Hope below code is will help you.
Please write a code like below..
PARAMETERS : R1 RADIOBUTTON GROUP G1 USER-COMMAND CMDDEFAULT 'X',
R2 RADIOBUTTON GROUP G1.
PARAMETERS: FIELD1(30) MODIF ID 'AA',
FIELD2(30) MODIF ID 'AA',
FIELD3(30) MODIF ID.
AT SELECTION-SCREEN OUTPUT.
LOOP AT SCREEN.
IF R2 = 'X'.
IF SCREEN-GROUP1 = 'AA'.
SCREEN-REQUIRED= '1'.
MODIFY SCREEN.
ENDIF.
ENDIF.
When select R2 field1 and field2 will be Required.
Arivazhagan S