Pregnant sister suffering domestic violence from husband and in-laws

Hindu religion. My sister case: My sister is abused financially by her husband.He demands that the entire salary of my sister to be transferred to his account.When my sister opposed, he threatened her to commit suicide and banged his head on walls continousuly.From then on his parents and his sister continuously started torturing her that you will not give money etc. When she is pregnant 8 months, he hit her and tried to burn her with spatula. After delivery, he hit my sister since she opposed him and tried to hit my parents when they tried to stop him. Beyond this he continuously tortures her telling that you dont love me and you will leave me and go even if she tells constantly that I love you.If my sister didnt ask how he is, he will immediately accuse that you dont love me. Constantly he will bully her into doing what he wants and not what she wants. He has demanded her to cut ties with her parents and family and monitors her conversations with everyone.