Family property dispute

We have a small ancestral property in Guwahati Assam, i have a younger sibling who works in gram panchayat , i am the eldest daughter, I started working since the age of 25 , took an educational loan on my own to pursue my higher studies. I used to diligently pay my emi’s plus send a healthy portion of my salary every month to my parents and my sister who was then unemployed and stayed with my parents, i got married and settle in Mumbai with my husband and my kids. Last few years i have seen a noticeable change in my parents behavior, my sister manipulated and coerced my father to stay away from me. I have given so much to the house irrespective that I have a family here in Mumbai. My husband helped them personally with a huge sum of money to build a house on our land but at the end my mother and my sister conspired against me and have blocked all the ways of communicating, they have threatened before that they will remove me from my fathers property which I have a right, i have given much to That family mentally physically financially, they are now planning to sell off the land without informing me and i am sure they will not give me any share, i have a deep connection to that land since its my father’s and i was raised there, please help I even do not have any idea if they have sold off the land