Uncle trying to capture land forcefully

My father along with his 3 brothers had division of land after death of my grandparents. As my father is the elder one, it is common in the village that the elder one gets a little more land share as he performs the last right of parents. So during the division my father got a little extra share then the other 3. It was done all peacefully and other people of the village were also present during the same. Now what happened is, my father had purchased a land on his personal income in a different town. He made 4 rooms there and this rooms were rented. After some time one of my uncle came and asked my father to give him a room so that he can go to his company for work and will just live there for the job only. Everything was fine and as my father was elder of them. He always supported them. Slowly uncle started living there with his family, he has 2 son. He then asked my father that we should divide the purchased land too. My father said as all of them were brothers and to maintain harmony he divided the land into 4. All this happened just verbally and no paper work done. Nor any person was there . Just 4 of them did this. Currently the land is in my father's name only. After all this. My uncle built a house in his area. No issues were there. But now he started construction in our area of land. When my father went there with the other 2 brothers. My uncle said that he will do whatever he wish to. And threatened my father that he will see him and bring my father to the road and many things. Initially my father didn't share all this with me. We are family of three only. I am currently studying and preparing for govt exams. Due to this my parents didn't share all this to me. Now when I came to know, i got shocked. I got to know that my cousins also threatened my father. As i am 23 now and busy with my studies. I don't know what should I do. I have no idea. My parents are in tension. I want to take every possible action which I can. But as I am not aware of legal system. I request you to please help me out. What are the legal action for the land issue and the action which I can take to safeguard my parents. My father is retired and I feel bad as i am helpless. I feel contacting the local police station but get ignored. So please help me.