love and marriage

Whatever you and the girl want to do. Of course, this could be complicated depending on the societal customs of where you live (you did not say but I am guessing you are not in the US.) But assuming you don't need their blessing, then it is up to you and the girl what you want to do.

is your name Romeo? Is hers Juliet?

You should sit down and explain your feelings to your family. I would talk to your family members on a 1 on 1 basis, that way they can't gang up on you, or reinforce each others hatred for her family.

yeah it depends on me and girl, but i am living in a combine family.
how i convince my family?
i really love her

yeah i tried to explain but my parents says that i can marry any other girl, but not with her (my love),
actually her family hated us when we were financially weak, and they also refused the proposal of marriage of my elder brother and their girl given by my parents about 3 years ago,
now i tell you my problem with detail,
whats you say about this?

If you are old enough to get married, then get married and move with your wife to another town so you can live in peace.

Your family is controlling your life. Do you want this?

I would say that these are problems between your and her parents. If you both love each other I think that you should married. If you think that you will be happy with her then act and don't worry what would others say. Everyone deserves to be happy