Procedure to get the property divided without any dispute

I m frm hindu famly, v r 2 sons and 1 daughter for my father. My father ernd a proprty from his own earnings. He expired without sharing or riting any will. After his death it was decided within our famly members that the proprty will be shared 5 parts, 1 for my mother, 2 for me, 1 for my brother and 1 for my sister. Later my brother also expired before sharing. Now I wanted to make it clear to everyone and share the property so that there will not be any dispute later as per the discussion had. But my sister-in-law famly is not showing any interest in processing the arrangement. My question is my brother has 2 sons who are going to get major in some years. When I am ready to share the property as discussed within the family, if my brothers sons can raise an issue that the property is only 4 them and no share to be given for my sister or me, I don't have children, my sister has 1 son and 1 daughter. Bothered what will happen next if my bother sons file case against us.