Different culture has different approach. Any advice might be appropriate to most but not to some.

Well, communication is very important. You must open up with your mother in law and tell her the truth that you two are married. There's no such thing as to choose whether his family or you because if they like it or not, you are already part of his family. At first, hatred and anger is normal in your situation but eventually they will accept you at the end. Soon there will be understanding especially if you have a child. "Grandparents always loves their grandchild."