My grand father had land in village called phulaguri. His 3 sons should get equal amount of land. Wh

My grand father had land in village called phulaguri. His 3 sons should get equal amount of land. When my father was alive the land is not devided among them. But now my father is expired and we asked our uncle for providing us the paper of the land. But they did not give us. They told that they have taken the property which was supposed to be in my father's name. Please advice how to proceed legally for taking back our land