Sister being harassed mentally emotionally by in laws and husband

My sister is continuously being harassed by her mother in law. And her father in law called my father and shouted saying to take my sister from her house. Husband says if she has to stay then my sister has to obey each and everything whether she likes or not. Her husband doesn't allow to touch his phone also. Her in laws always say that they would marry another girl as their daughter in law. My sister has lost weight and is mentally and physically sick. marriage had taken as per hindu rituals. When my sister told she is sick n take her to doctor, they said they have no money n demanded money from us indirectly. I want pull them to the court n punish them n recover all expenses of marriage n also her maintenance n expenses.how can we proceed?