How can i claim my property in equal shares

Dear sir/madam. my family consists four people our native place is devarapalli, which is in Krishna district, andhrapradesh.we currently live in Hyderabad.me (SON),Mother, Sister and my father.my mother married to my dad on 1990 and we were together for 27 years .my father left us due to his personal reasons 3 years ago. before he separate from us he promised us that he will share our rightful property. we have three lands in our village .out of which two of them are farming lands and one plot area in our village. But that time our property legally named after my grandfather. that time we insisted my grandfather directly name our property to my sister and my self. to avoid double registration. since my father attitude is not stable for some time he says "I don't want a penny " other time "if i give entire property to you what will i eat". so we try to convey my grand father to register two of farming lands on me and my sister name. Grandfather rejected and father changed his words at our village stating first register in my name after that i will transfer to you he said. so after a lot of thought we decided we will do that later. but soon after my grand father died.my father and their two brother registered on their name without even lettings us know. my father stay separately we have no contact from him but we know we he working and where he staying from the relatives.my father give his farming lands to rent. his brother farm those lands and pay us rent. after separation we never bother about farm land rents and all. now we find he was with another women and so far we know that he saying to her that his old family(Which is us) was dead long ago. she called one of my father brother and enquired about our living situations.so we were worried that he will misuse property more since he claim he bought a big gold chain for her .we contact one of our relative at village he contacted our father and said he will write his property in our names. He want us to come to our village on coming January so he can register in our names. But his attitude and character is not trust worthy at all. We tried to contact other big heads in our village. they were suggesting that since my sister need to get married . we should register one of farming land in her name and another farming land in my name but I'll get that land claim after his dimise.my mother won't get anything for now they say. since my mother know that he was with another women she wants her fair share too. if we went to village and he rejects everything what should we do. how we should proceed further to get our property. it would be great help to if you put multiple suggestions. Thanks and regards kiran