Protection of self-dignity

One of my cousin is going with a tough time due to her husband behavior. He is not taking care of her for last 6+months by saying he does not have any money and have a lot of debts to pay. Earlier they both were living in chennai later on he moved to bangalore saying he has got deputation. My cousin was also working in chennai so she was forced to stay alone and he continued to pressurize her to shift in PG. Now she got an opportunity in bangalore and informed her husband but he refused to stay together saying he don't have money to take rental accommodation and forced her to stay in PG. In last four years whatever she has earned has given to her husband and he always mentally pressurize her that you have not bought any thing from your house. Her in laws only giving her moral empathy and they are not talking to their son on this behaviour and forcing her to adjust the situation. Also in last few months he is opting for PR to go Australia or Canada and recently she has heard that he has got Visa for Australia. Also her parents has tried to talk to her inlaws but the situation is not getting better. Can you please suggest what should be the correct action or step? Also as a parents what steps can they take as they are staying in other state? Is there any action can be taken to put a stay on the visa so he cannot fly? Or what can be done if he flies to other country?