Maternal Grandfather s property

Dear Sir I have a question. My maternal grand father and grandmather died without making any will or distributing the property to his 4 childs (3 daughters and a son). And after that my elder aunt died in the year 1992 keeping 3 living daughters and of them all are married now. In my maternal grand Fathers property my uncle (mama) and my unmarried aunt (maasi) lives. As my unmarried maasi intending to stay with us hence she wants to make a will in favour of my mother from that joint property from her portion. Kindly advice if my aunt have any right to execute that will. Also does my mother, who is alive can claim her portion of property? Also can my elder aunt's who died in 1995 can claim anything from that property? kindly advise. Regards