One way my counsellor had told me was to sit with your parents and ask them every possible reason why you should not marry with the one you love and just listen calmly.. dont oppose or say anything.. just let them pour out everything.. do this everyday.. and one day when they finish up with all their doubts they will agree to your relation! Try this.. it may work for you

First of all , Indian parents are egoistic. That is where all the bug bites

Sometimes they oppose to test how strong your feelings are. Just follow what ajwain says and be cool.