My grandparents are being harassed by my uncle n aunt

My parents, grandparents and uncle & family live in one house but separate households. My "Chachi" is an extremely notorious woman and has been causing troubles in the family since she got married. It's been 20 yrs tolerating her nonsense... She does not want her husband to keep any relations with his parents and if at all my grand mother try to talk to him or ask him to do them a favour, she comes and fights and abuses with foul language. Yesterday, the situation went out of hands. My father and grandmom requested my uncle to go to Delhi along with him, for my grand fathers check up. He said OK... But when she came to know she came down and once again started abusing. My father heard this and came to see and saw that she was grabbing my grandsons hand and trying to hit her. He pushed her away and she fell... This angered her more and her son 20yrs old came and both of them were tried to hit my grandmom. My father was protecting her so they attacked my mother instead and the boy slapped my mother and aunt scratched her. So what I want to ask u is what is the law that protects Senior citizens and their property and under what law can they be forced to leave this property? The crux of the matter is that they want this house and want us all to leave. It's an expensive house and they are eyeing this property from the start.