What should i do please advise ?

Hi, My MATERNAL grandmother had a property in lucknow. she died with out a will. she is survived by 6 son and 3 dauthter of which 2 daughters have passed away. I'm the son of one of the passed away daughter ( i.e my mother who passed away in 2001). recently ( 1 week ago ) i came to know that my maternal uncles have removed all the daughter's name and produced proof that my grandmother was survived by only 6 sons. and they are moving ahead with mutation procedure so that they can sell off the property. 1. Do i have the right to the property that belonged to my grand mother and my mother has also passed away in 2001. ALL OF US ARE BASICALLY FROM WEST BENGAL. 2. what do i do? 3. I have already deposited the proofs of all the nine share holders to Lucknow Development Authority and they have stopper the file movement as the documents in the searching reports were false. 4. Now as i stopped the file they want to come to a written agreement with me. PLEASE ADVISE WHAT SHOULD I DO THANKS Arka