How to stop the torture of my brother and his in laws

My elder brother got married in 2009, but since then that couple is not in good terms. They started domestic violence also.Then His wife went back to her parents due to daily torture of each other,Now her parents has started torturing my brother to get the house in same city.to stop this daily torture My elder brother did the same and bought property in His in laws city.Now one thing has started leading to another.His in laws wants to get that property from him and forcing him to give it to his wife on legal basis. Because of this my brother has undergone in depression and he has started torturing my parents. He doesn't want to live with his wife but because of his son he is sacrificing the situations and his in laws are taking advantage and insult him daily. this is happening from past 8 years. If he is going for divorce, his in laws are asking huge amount so he cannot choose this option also because of financial crisis. His father in law now has started torturing my father over phone.Because of this whole main situation he has started torturing my family,. he is thinking like my parents has done this with him. he is getting mad day by day. Please suggest what should we do to stop this torture.