Property disownment

We are two sisters am the eldest and married for 10 yrs while my sister is a divorcee and is living with my parents. After I started working which is prior one yr of my marriage my parents expected financial help from me monthly and slowly exploited me with false reasons after 4 yrs I realised and parted from them. My father received immovable property share from his father 3 yrs ago. 2 yrs ago my father came to me and apologized and promised me to return all the money by selling off property and took consent from me to sell off a site. In the consent letter their was no mention of monetary terms but my father promised orally and I gave my consent. After the transaction he dint give any to me but after 3 months aftr our repeated arguments he gave Rs.3 lakhs and told me that site was sold for 12 lakhs. Recently which was much Later I got to know that he sold for 20 lakhs through relatives. Now he wants to sell off a property which on papers it seems self acquired but my grandfather(living 80 yr old) gave money for it and wanted my father to register it as a joint property between my father n grandfather. But my father dint obey n registered in his name only. This property he wants to sell and promised me to give Rs. 35 lakh against a property worth Rs.1.2 Cr via gift deed which he had earlier promised me to transfer the ownership rights to me and my sister after he n my mother would be no more and I had agreed. He has received one more property agricultural land from my grandfather which is 7 acres he wants to sell off that also as per my mothers wish. My wish is we are only 4 in a family mother father n 2 sisters and want a fair secured share for all. I was never selfish and their wish was my priority but their offlate unfair and falsehood deeds have hurt and lost trust in them. I want to claim legally what am entitled for and pass it onto my son. Pls suggest me the best options.