What action can be taken against wife's family if they are causing issues with my married life

Hello Experts, I am married since last 5 years and recently become father of a baby girl. In initial 2 years of our marriage we were living a good life with my wife and parents. But due to some conflicts between my wife and mother, wife started visiting her sister frequently and now we are at point where I am being threatened by my wife here and there about leaving the home and living at her sister place. Important to mention that because of the unwanted support to my wife from her sister, I had to seprate my 70+ years old parents to a separate home and now they live alone, though they are close to my house and I try to take care them as well. This seperation caused adverse effect on me and my parents mental/emotional health and they are forced to live alone. Please note, they must live in Bangalore as ky father is suffering from critical liver condition, so they can't move back to our hometown. Also important to mention that they are not financially dependent on me, both are gov retired and get enough pension. Over the years my sister in-law has an damaging effect on my wife. She takes example of her sister in everything without understanding my family situation and the way we manage our life. Sister in law has a rich husband and extremely arrogant, same has been started reflecting on my wife over the time. While I know my wife was not like her sister, I am in very bad situation where I am not able to take care of my responsibilities for my parents and wife/daughter together. I feel if interference of sister in law can somehow stopped, I can live a better stable life with my wife kid and parents. What legal action I can take against my sister -in-law and save my marriage from a possible downfall? Please advise.