Senior Citizen Harassment & Domestic violence

My husband have 2 elder brothers both living in Delhi in one building (down stairs/upstairs) & we live in Haryana on rent due to my husband's job. The property is at the name of my mother-in-law. From the starting my mother in law was very much attached with my second brother-in-law and always happy to live with him. However, we both (my sister in law & me) never took objection if she wants to stay with us. My second brother in law was married after my marriage as earlier he was not ready to get married. After his marriage things were going well for only 6 months after that we saw different face of my sister in law. However, they have one son also who is 8 years old now. She was having relationship with another person outside and now she only want to have property and want to stay with his husband only for the property. My mother in law who was already very attached with my brother in law simply denied both of her other two son's that she is not ready to give anything to him (that means my husband and his first elder son). We just leave the matter as it is & didn't say anything to her. Now it has came to the notice from some sources that my second sister in law start beating my mother in law as well as his husband as she want hold of entire property. And very surprisingly my second brother in law has not taken any legal action uptill now. Earlier also there was so many fights between both of them and there was police complaint also but nothing happened to any of them and the things remain the same. Few months back both of them have a big fight or may be drama & my second brother in law insisted us to take the mother in law to our house and I bring them to our house. She stayed with us for 2 months but after that she told us that I want to go back to second son as she can't live without him and she is very worried about him. We tried to make her understand that you are not safe their but still he told us that I am ok staying there. However, to our surprise during those 2 months they don't have a single fight. When we took him back the fights started again and now just yesterday my mother in law called my mother and told her that I am not safe here. My husband and my first brother in law both are govt employees and my second sister in law once threatened my brother in law that if he will do any complaint or anything against her she will file any illegal case against him that can led to loss of his govt job. Due to which my brother in law is not actually ready to take any legal action. As we are not staying with them and living in other state police will not consider our complaint. Now I want two things : 1. Safety of my mother in law which is very very important. 2. Something against both of them who are playing game with my mother in law. My mother in law is taking pension from past 22 years and all the accounts details are with his second son. However, he never care for her as she required. His only aim is to increase bank balance