Ancestral property - grand father's property

Hello sir, Im Srinivas Pathak. I have query regarding my ancestor's property. Here is the description : My grand father, Manmohan prasad, had 1 brother and 3 sisters. He had some acres of land in a village called chukkaipalle, kollapur, in mehaboobnagar district, of telangana state. As my grand father's brother did not have any source of income, years ago, he verbally gave this land to his brother so that he can earn his bread. As of today neither my grand father, not his brother , are alive. Also my grand mother is no more. But the property is still being used by my grand fathers brother's children. Now my grand father has 4 children out of which, the eldest brother, has expired just 15 days before. My father stands number 3. My fathers second elder brother clearly said he doesn't need this property. My question is- 1. Do I have rights to ask for the property of my grand father? 2. My dad is not strong enough to ask for his father's(manmohan prasad's) property. Can Me and my mother take a stand and ask for the property ,bypassing my father?