What can I do if my brother sold our late mother's property in fraudulent way?

Hello, I'm Sharmila. I have 3 Houses. The houses are 1Rk in Thane and 2 rooms in chawl. All were bought by my late mother and also the property owner of all the rooms still my late mother. My brother have illegally sold the 2 houses of Thane and Vile Parle. I want the equal rights as well. My name is in the document(ration card) but still he managed to make the illegal papers. What are the procedures and also the charges just wanted to know. I heard from my relative that 25%of the property value goes to the lawyer. Is this true? Please help