composition delaer Gst no. cancelled. what about final return?

i had cancelled my 2 client's gst no. before 3 month. i got order for gst number cancel before 2 month. but still date i can't find final return online in clients loging. 1) my question is regular dealers has to file final gstr 10 but what about composition dealer after cancellation of gst no.? 2) whether composition dealer has to file final return or not?