How to protect husband from false allegations by wife

My brother got married 5.5 years ago. He was working with our uncle in Belize a carribean country. After marriage he took his wife along and opened a small business over there with uncle's help. But the wife is very ill behaved and treated my brother very badly from the past so many years. She does not cook and also do no household work and also mentally tortures my brother almost everyday. She also threaten my brother to file a case against my brother and send him to jail if her demands are not fulfilled. After so much suffering somehow my brother has managed to bring her back to India and presently staying with our parents from past 1.5 months. He does not want to stay with her anymore and want to file for divorce. She is also very ill behaved with our parents and here also she threatens my brother that if he tells anything to anybody then she will get the family to jail. How should we proceed? What precautions we should take before filing for divorce. We are planning to file for divorce and give a general diary to nearest police station and leave her to her parents house. What will happen if after receiving notice she files a false case under 498A. What can also be done if she comes back and harasses our parents and try to get inside the house. In the home my mother is 56 years and does not keep much well, father is a dialysis patient from 4 years. Also bed ridden grandparents are also in the house. What remedies we are having? Please give your valuable suggestions.