Hi Raj
You have to decide what means more to you, your family or this man. If being with him means you will lose your family, will you be able to cope with that, and are you sure that you will not resent him for it.
On the other hand, not everyone finds love, so if you have found the man you love, then you should go for it as otherwise you could end up in a loveless marriage and never be happy.
Perhaps once you are married, your parents will learn to accept you, it often happens after the children are born.
Good luck!