How to cancel RTC without death certificate of my grand father ? Can we do that ??

Dear Sir/Madam, As per the subject concerned, My mother has property ancestral property in brahmavara near udupi. It belongs to my mother's father. Currently RTC is in my Mother's brother name. My mother's brother he's selfish, not given any piece of land to my mother. As per the law my mother will have equal rights, but lawyer is asking death certificate of my Grandfather(Mother's father) to cancel 'RTC'. I've few problems: 1) Either my mother or myself doesn't know the death date of my 'Grand Father' but my mother's brother transfered 'RTC' to his name. 2) How to cancel RTC without death certificate of my grand father ? Can we do that ?? 3) Officers in our village not responding since from 1 year, they're not providing details of my grand father's death certificate or they're not disclosing how my mother's brother got 'RTC' Transfered to his name. Please answer to all these question, since our lawyer also playing the game with us & he's not helping with this queries. We've great respect for lawyers and please guide us.