Properties on my grandfather name

My grandfather passed away in 1989 and he had few agricultural land and a house on his name. My grandma passed away in 1993. My father had a elder brother and two younger sisters. After my grandma’s death, all four decided to split the properties, and daughters took a big Agri land that was on my grandma name. My father’s elder brother got few small size Agri lands and 50% share in house, same for my father. Then my father’s elder brother sold his share of Agri land to some third party and 50% share in the house to my father. But he wrote the release deed in 5 rupees stamp paper but not registered. He passed away in 1997. Then my father passed away in 2012, after that I realised that our share of the properties are still on my grandfather’s name and I applied for patta transfer but it got rejected. We got legal heirs certificate to my grandfather in 1998 showing only my father was a legal heir to my grandfather. Vao is saying that legal heir certificate is not correct and it was issued only for electricity board name transfer purpose. Now my father’s sisters also asking for share in the properties because our shares are still on my grandfather name. Please advise here as how can I save our property.