Ownership and sale of property

My mother is living in Amritsar,Punjab in a house she came as she got married in 1974.In 1984-85 my father and two of his married brothers along with my grandparents left the house as such(because the neighbors and village people supported my mother as they tried to kill my mother but later divorced her and secretly married in city in his new house that was again constructed secretly.) Since then my mother along with her three daughters has lived in that house only though they tried to threaten her many a times but we survived.The house has been taken care of by my mother only and high court had given the stay orders to my mother to live there.They never turned up to maintain the house or pay any house taxes and even failed to set us out of the house .Now again they have started the same process of threatening my mother who is living with her youngest ,mentally retarded daughter,and my mother has no power now to fight with them anymore.so I want to bring them to Delhi to me but leaving the house means leaving possession that will be in their favour so how can we claim our share or how can we sell it as the house is not registered in any name but they have made fake registration papers in my grandfather's name who had expired around 10-12 years back.They didn't claim anything that time also