Advice on handling domestic violence

Respected Sir's, Thanks for all the advise. As i mentioned in my previous query can you please advise if there is there any precautionary measures that my brother in law could take before my sister would take support from the Law against domestic violence. Hope they stay happy but in worst case if she can't take it any more and before her is there something my brother in law would do to safe guard himself? Why I'm asking is, my brother in law already is in talks with the lawyers but our family is still thinking if we should also opt for lawyer help. Thanks!!