share from property

My question is regarding house of my father. We are 5 sisters 1 brother. Both father and brother are not alive. Brother has 3 children but my sis-in-law got married after the death of my brother and left our house. Now she is trying to cone back though she herself has no right but we dnt have any proof of her second marriage. She is theeatening us that she will entered in the house forcefully. My mother is alive and live with me. We want to give my brother’s chuldren there right but ince that lady enteres in the house she will sell it without legal documentation. None of my brother-in-law is willing to take intiative of selling the hoise though the property rights have been transfered to all of us. Kindly guide me what should i do? Can i get a stay order from court? If i want to get my share to whom I have to send the notice? Plz guide me