How to initiate division of ancestral property

My grandfather(expired in 1997) got second marriage after expired first wife behind a son (my father). My father expired in 1993 behind my mother, sister(married) and me. 3 sons and 5 daughter(married) are from my grandfather's second wife (expired in 2005). A property in name of my grandfather has no will, was constructed in 2013 (four floor) with mutual understanding and divided into 3 sons and us to each floor, we have first floor which constructe by me. Papers is still my grandfather's name. Now they all don,t want to transfer first floor in our name. I want to know that What is right of my mother/me in property? And their others? How can I get papers titled in my/my mother name? How can I sell first floor? My mother is more than 62, what papers should I have to get from mother for future in her absence. Any other suggestions pls.