Will Getting Divorce in Australia be Valid in India?

My cousin is living in Australia from last 10 years. He went to India to find a nice girl in 2014&he found one & got engaged & did a court marriage. He applied his PR (in 2016) & added his wife as a secondary dependent & she got PR because of him. Now last year, they got married with Hindu rituals. No dowry was taken by him. His wife lived after the marriage only for 10 days with the parents &there were no issues with in Laws even she misbehaved in many way but my uncle & aunt ignored those because they thought she is only here for short time. She arrived in AUS in Oct & after 2 days she started asking his husband, we should move to Queensland (Cairns) because her relatives are living there. She started annoying him on daily bases he said I will check that option. He said it’s a small town he cannot get a job as an IT person there. Anyway she knew this. Her relative visited them & they said they are thinking of moving to Brisbane why you want to move to cairns. You husband have a good job. After that incident she started saying I want to move back to India, they did all the counselling with family, friends but she was stubborn. He suggested her I can get an admission in a college to do study but after attending 5 to 6 weeks she stopped going & said I will die but won’t go to college. She demanded on that night I want to go back to India right now (2am) he said we will talk in the morning. He asked her if you are feeling home sick then you can go for 1 month & come back. She said I want to move back to IND permanently. They mutually agreed that they want to get separated. She signed the lease papers to take out her name from the house lease. She booked the tickets to visit Cairns. Her relatives paid for that. They both signed the Stat Declaration (Stamp paper) in front of AUS Police officer stating they are getting separated from today because she doesn’t want to live in AUS. He tried to change her mind but she said it won’t work. After few days she started saying she wants to come back but also started harassing my cousin’s family. She said you will have to work my way or else you will have to come to India for divorce. He started ignoring her calls & messages then she started calling his friends, family &started harassing them. Now her parents have filled report against my uncle & aunt (in laws) saying they have harassed her & my husband is not accepting me because of my in laws. Her parents are saying those paper she signed they got it signed under pressure which is laughable because she signed in-front of the police. Police have called & threatened my uncle & aunt saying they will cancel his passport if he will not accept her. Australian police is saying she can do whatever she wants but if she annoying you then get an intervention order & of course what she has signed for is true, she cannot say she didn’t know or she didn’t sign those papers. She can charged if she say no in AUS. Any suggestion?