Ancestral property

My grandparents wrote their will and gave all their property(old house) to my father. My father & mother demolished and built shops and house on the same land. Now my 4 aunts and 1 uncle (they all are settled and live separately with their families) are pressuring my father to divide the property which my father doesnot want, as he had paid all money to built the house and taken good care of my grandparents till their last breath. Since the will and registration of house is in my father's name, my relatives are putting false complaints in police station, in women's counsel against my father,so that he pays them some money in return of property. Also they went to muncipal corporation for doing "namanataran" of our property(which has already been done by my father after the death of my grandparents). Please give me solution to end these everyday torture by our relatives. My father doesnot want to give them any money in the name of settlement. Every time whenever there is some good function/event at our home, they bribe the police constebal and asks my father to have his presence and give statement in police station. And nothing goes without bribing to the police, even if you show all the proper legal documents. Because of these my parents are afraid to leave town,go anywhere to meet people,take vacations outside town just in case if any of the relative posts any selling ads in newspaper or bribe nagarpalika officer for another namantaran in relative's name. Your advice would be helpful. Thank you.