how i convince my parent for same cast n gotra love marriage

Plz help me out...am in love with a guy of same cast but the problem is we r in same GOTRA....We have same surname with diff sub cast...parents are completly against bcz the same surname n all...so plz give me a suggestion..how i convince my parents for this marriage..plz help

Hello friends
I'm in love from past 5years
I really want to marry him
But unfortunately we belong to same Kulam
Can u al help me to give idea to get marry