Husband harassing physically and mentally. What action can I take?

My sister is carrying 2 time and walked out as her husband keep on beating every day and came to our home due to repeated domestic violence by her husband, mother in law and 2 sister in laws....this issue already went to lok adalath and husband promised that he will not harass by boozing, beating and taking care of basic expenses of their 3 year boy still he is repeating the same. We did not send her back when he came to take her as he was not buying basic medicines for her pregnancy, He clearly told he don't care of her and children.. Now we called him - he is disconnecting calls as he will be much needed as my sister will be admitted to hospital soon for delivery. When we asked him why you have beaten and harassing - he said I did not do anything - my sister is lying, and about medicines, milk for kid, and basic needs at home, he kept silent. we never went to any police stn /court - due to his attitude we were helpless and went their and don't want to go again,advice pls