Hey bro I hope you arr okay and you are doing great it’s really difficult to fight against bullies and even trying is great.
First of all gathering physical evidence is the top priority as screenshot of chats is usually not considered a viable evidence. Try to collect images of physical abuse and if possible, try to document injuries or marks with clear photos and a timestamp โ even better if you have a witness or medical report.
Keep your phone recorder on around him, if not that buy a recorder which doesn’t look like a recorder.
Once you have enough evidence contact an online journalism group which will post your story along with evidence on various social media platforms and do the same for the news company which is the direct competitor of your bully’s company also file an FIR with this evidence.
Best of luck man, you can do it.