Sharing Problem

Dear Sir, This is santosh kumar s., from andhra pradesh, india. i need a clarification from you. My father is a retd. govt employee (retired 8years back). he has three sons only, which I'm the eldest. i'm a private employee. the other two brothers are govt employees and we three got married and have children. two years back my mother expired owing to ill health. now the younger brothers have sent a legal notice to my father asking him to divide the property into four parts. but daddy (as he himself lacks his left hand), with my suggestion married and i advised him to keep the property for himself and his wife and that we are employees and can earn our living. My mother is a house wife and never worked but supported him till her death. we have only two houses, but as he is a govt employee, he made the agreement as that his mother in law (my grand mother) gave it as a gift to her daughter (my mother) and registered to gift deed. so i need your suggestion in this point can my father take right of whole property and sell them without our permission for his future livelihood (he is getting a pension of Rs. 18,000)? but my 2 younger brothers are not listening to what i say or convince sir. I'll be waiting for your reply. My mail address: mailsntsh@gmail.com