Husband Is Playing Mind Games On My Sister Within 1 Yr Of Marriage

Hi, I have a sister who got married last year in November '2017 but since then both of them (my sister and her husband) had been living separately. Actually, her husband had lost his job just 1 month before her marriage in Oct 2017 (dont know if its true but this is what he tells us) and since then didnt get a job until June 2018. Also, since June onwards, her husband had been playing a lot of mind games with her like not talking nicely to her and not treating her well. He even went on spreading all kinds of lies to his family as well. Now, he have blocked her phone on whatsapp and is trying to avoid everyone's calls. His family is also not very supportive and keep telling my sister only to cooperate and compromise. Please let us know what can be done in such a scenario. We dont even know where does live in Delhi and dont even know his address where we can meet him. His family is not ready to give his address to us and telling us that they dont know themselves.