Property Dispute Help Please

My grandfather had three sons and three daughters. He passed away when my father was around 3 years old. Before his death, my grandfather transferred all the property to only his three sons. This property was earned and not ancestral. One of my father's brothers has already passed away without marrying or leaving any will. Now, who would inherit his share of the property?
The property has not been divided yet, and the deceased brother's name still appears alongside the other three siblings on paper. Now, with my grandmother still alive, would she be entitled to that share? The situation is complicated because another brother of my father is suggesting that we sell the entire property and divide the proceeds in the ratio of 1.25:0.25:1. Here, 1.25 represents his share, 0.25 represents my grandmother's share. However, according to my understanding, his claim extends to my grandmother's share as well, leaving us with only 1 percent.
If we refuse to sell, he threatens to convince my grandmother to make a will leaving her entire share to him, which he claims to be one-third. Since the property remains undivided, he also intends to divide it into three equal parts, effectively taking the entire share belonging to my grandmother. Can he legally pursue this course of action, and what steps can he take to gain control of that share? Furthermore, is it possible for him to acquire my grandmother's share without our consent? Also, are the daughters legally entitled to inherit the share of their deceased brother according to Hindu succession laws or any other applicable laws?
Additionally, we have some farmland, and some people have been farming there for three to five years. He tells us that he will negotiate with the farmers and take over the entire agricultural land, something called Barga or Bargadar. We live in West Bengal, so does anything like that exist where if someone farms your land for 3+ years, the agricultural land will become theirs?