What would you do if your 23 year-old son doesn't study, never had a job and hits you back (harder, hurting you) recently for the first time?

My brother and I were raised old-school with religious values. Meanwhile I didn't give my parents headaches and was already naturally shy (docile temperament), my younger brother was another case. My parents only raised their voice once at me and that was enough. That would get me scared easily without ever getting physical. They told me themselves (their own words) that I never needed spankings.

With brother, nothing worked. He was 15 the last time our father spanked him for backtalking and stealing from mom. He's now 23 years old but doesn't care about going to college, never had a job, doesn't even help with the household chores, can't cook and just recently knocked out (punching him twice, lifting him and threw him on the floor with a hard shove) my father, dropping him to the floor. My brother and father had a huge argument, my father backhanded him for derrogative terms he said but my brother hit him back harder. My father has a small bruise on his face and his back is a bit sore from that fall. That's the first time my brother ever hit my our father, flooring him.

Our parents are now at lost of what to do with him. Our father has paid for his Judo classes since he was 18, weight lifting and for his cell phone. He used his skill to knock out his father. What would you do?

Updates
3 mo
My brother doesn't feel remorse either.
Updates
3 mo
My parents want him out by the 1st of April. He'll get evicted if he doesn't leave by then. When my mother asked my father how he's feeling (with the back pain and bruise), he has two responses; he's feeling better physically but totally destroyed emotionally.. to have to deal with the shame of getting beaten by his unremorseful son.
What would you do if your 23 year-old son doesn't study, never had a job and hits you back (harder, hurting you) recently for the first time?
Post Opinion