Division of property after death of my grandmother

My grandparents have two children one is my father and a daughter who is my bhua. My bhua is married in 1991 and grandmother is the owner of our property. My grandfather died in 1991 and unfortunately my father also left us in 1992. Presently in my family I have an elder brother who is married and my mother. Since 1992 there has been brawl for property between us my grandmother and bhua ji. Years passed by and two days back my grandmother expired, now my bhua ji and her husband are saying that the property will be divided in half and have given us only a month's time to settle everything. We are asking them to show will or any legal document on basis of which they are saying this but they are not showing us anything. They are saying we have alredy done deal with the buyer and we need to sell half of the property within a month. What should be our first step in present scenario and what to do if they misbehave and do not give us the will and try to harass us mentally to do the settlement?