Mental harassment by sending abusive messages

My sister's husband kept on torturing her mentally and physically. He is an alcoholic and doesn't know what he does after consuming alcohol. One day he hit her. She dialed 100 the officer investigated and asked her to raise a complaint to the nearest AWPS. She came to our home and staying with us. My mother is taking care of her children. He comes to our home stating to see the children. Although we allowed him to see the children he is making unnecessary arguments and quarreling.  He kept on sending offensive messages using filthy language in email and WhatsApp. In order to frustrate us more, he took the screenshots of those emails and send them to all our relatives, and published them on social media. She made a complaint in AWPS they too warned him about this but still, he continue to do the same. We have a CSR copy too. Two years before he filed a divorce case. His relatives requested us to give him one last chance. Later he himself withdrawn the case. Now my sister has decided not to live with him. He and his father have taken more than 25lakhs of her money and bought all the properties in their name. Now he has left his job intentionally.