How to proceed for divorce by the husband if wife neither want to stay

My bro, a police officer gt married to his fellow officer on 10th Sept/2015.They gt introduced to each other in their training period & gt maried as per special marriage act.Frm beginning ,she used to insult my bro and my mom as we r bengali muslim and she s assamese muslim.She even insulted my bro dat he s not fit to b police officer.she don't want to live wd my mom.So many cruelties towards d family.She left our house on 25thAugust/2017 on trivial issues.On 8th Novmber/2017she gt arrested for job scam(whenever she was asked abt d incident as news papers were publishing her controversies,she used to denied)& gt bail on 7th October/2018.My bro went to meet her at her father's place but she didn't meet.Some common frnds also meet her and discuss d matter.She says she wl neither return nor wl divorce him.Now d matter is pending.Many times we went to discuss d matter to solve on mutual consent.She nd her family s not willing.They say dt they won't allow my bro to have a peaceful life.