About property

I am 28 years old girl and My father is in wed lock relationship since past 25 years with another women and they have son also, my father has always been very abusive towards us n always tortured us for money n he even refused to pay for my education. where he is bearing all expesnses of that boy n sent him to study abroad, few years before my grand mother died my father's mother and he dint even inform us n kept lying to us about her death. but we found out somehow, then the matter came of her will he again kept lying n after two years he sent us a will where its written that my grand mother has disowned us (me n my mother from her property n everything is on his name) and there is a sign of two witnesses one is some random women and another is his wed lock wife on the will , can you suggest me what legal action i can take against him for property? as it is earnd by my grandmother not by him, in will which he has sent us there is mentioned that one house my grand mother has given to my mother which he sold immedietly after my grand mothers death (and he dint show us will till then he sent it after one year of selling that house) and he took that money so what legal actions i can take against him as he has really ruined our lives. and tortured us in every possible way