Ancestors property

Hello

 I am an MBA student. I reside my late grandfather's house (which is still registered on his name) in Delhi.

 My grandfather has three son (out of which youngest one is not alive).My grandmother trick brothers to fight among themselves as well as with their wife.

When I returned after completing my graduation I saw all this and opposed her, result she (grandmother) started provoking her son against me .I am threatened to throw out of house with my mother and sister. My father remain drunk and completely in her (grandmother) control. By the advice on lawyers club I realized that they can’t throw us out.

But now my grandmother started ways (like she wanted to get house chemically washed, repair...etc), so that she could get us out of the house or disturb in my studies.

Please help me know ways, I can save my family from their tricks and the legal rights I have on the house which can save my family from my grandmother's pagan tricks

Thank You