How to save my brother from false domestic violence case

My brother got married in last year in Nov and in Feb they both shifted to Gurgaon as they both were working from home and my bhabhi's mykaa is there. she claimed that she want to have peaceful life and made my brother fight with my parents. Now from last 8 months they were staying in Gurgaon and during those month they both didnt spoke with my parents. But few days back she called and told that they both had fight and her brother and sister who lives there picked up her from my brothers house while he was speaking to her mother. In evening when my brother went to talk to his wife and resolve the fight her siblings didnt allowed him to talk and even insulted him. After that my parents wanted to resolve their fight and spoke with her but her maternal uncle threatened to murder my brother and my parents. my parents got scared and immediately booked flight and reached gurgaon to persuade her and to resolve the matter and even called her parents. But from that day nobody in her family has spoken to my parents. They even went to her brother's and sister's house to talk with them but they didnt opened the door even when they were present in the flat. Than next day my brother came back to our home but my parents stayed there for 2 days to talk with them but there was no response. Even when my brother tried to talk with her she was saying that he has assaulted her and shown picture of scratch in her neck and said he wanted to kill her. My brother again went gurgaon to talk with her and his family but they didnt let him come in. he stayed outside her brother's society for many hours. then her father told my brother to go haridwar to her mama who had did her upbringing and my brother rushed to haridwar and even their they didnt let him inside house he stayed outside in car whole night. in morning her nani ji let him in but then her mama told that go back to gurgaon even they didnt helped. Then my bhabhi messaged my brother that she will return when she wants to return. after returning gurgaon her parents told my brother to give written proof that you will not fight with her and then we got scared because this way my brother will get live his life in fear as we dont when again they will fight than again she will threaten my brother so he denied and told her to come back home. Even my parents messaged her to come back. Now today she have filed FIR against my brother of domestic violence. Please help what we can do