Civil Suit

Hi, Need advice on below . We are Hindu family of Western Orissa. I am the son ( age 34 ) of 1st wife of my father ( Yes my Mother is alive and we are one brother ( 34 years) and Sister(36 years)). My father did some physical abuse to my mother multiple times and she left my fathers house on 1985 and leaving behind we both kids on our Parental Grand Father place. By profession my father is a lawyer. My parental grandfather requested my mother to come and join the family in my parental side and she came after 14 years i.e on 1999 and keep staying with us ( i.e we 2 kids my mother, grand father and grand mother) . My father got married again on 1997 with out giving divorce to my mother. The livelihood of ours i.e we 2 kids and my mother used to be borne by my parental grandfather . Now we all are married and settled in our profession . My father has inherited 22 acres of land from his ancestors . On his 2nd wife he has 2 kids i.e 1 Son ( age 19 years) and one Daughter ( age 23 Years) . I have below questions 1. How can we claim our share of property 2. How much we can get from the over all share ( 22 acres in total) 3. What is the process of doing this 4. How long does it take Note- I am 34 years old and my sister is 36 and till now my father has not done any thing for us i.e No maintenance, No educational maintenance, No marriage expenses nothing. Also as on today we all are alive i.e my all parents and all siblings .