Domestic violence

My sister got married in feb of 2019 and moved in with in-laws and my brother-in-law (bil) used to live in pune .around may 2020 my sister moved in with bil . 15 days in, bil started verbally abusing my sister body shaming her, telling her she was wrong with him . Then came ignoring my sister , there was no communication from his side till this day . They live as strangers in the same home.and is trying to pressure her to initiate divorce from her side. There is also no physical relations to this day (2 years) We tried many times to act as mediator between the two every time bil agrees to try to change and save the relationship but does shit. He raises petty issues as food not good or argues back when he abuses her as his excuses. If my sister tries to save the relation .he beats her or lifts utensils in order to hit her. 1) on one instance he bit her on her cheeks in the guestroom of neighbours in their presence when my sister tried to kiss him. 2) he pulled her hair and held her forcibly through her hand and pushed her against on railing merely because she broke her curfew by 5 minutes (she was walking inside the apartment complex ). Here are my questions- 1) how long will the case take if we have proof of domestic violence in the form of medical report and a report filed of violence ( not domestic violence) in police station? We also have recordings of him admitting hitting him? 2) or how can we make him pay without divorcing him as he thinks he could do better in terms of life partner? In this case can he get divorce even if we do not agree even if both live like strangers due to bil not talking to my sister or living in different cities/ houses? 3) how can i make him pay as early(jail time) as possible ?