You should always have your brothers back no matter what happens in life. when you need backup, in any way whether it be a barfight or financially, your brother should and will be there for you--always. anyways, sounds like his parents fucking blow. They just caused years of psychological issues right then and there. If you are there for your brother to him out, everything will be fine.
Any parents who actually kick their kids out of the house can seriously fuck off. thats a real douchebag move. If he really cared, he would have never thrown his kid out of the house, and would try to help him on his way out to the "real world" regardless of belief differences on substance. now he deserves the guilt he's going to feel in time.
Not to mention if he helps his brother out, his parents might get stoked and try to get him back in the house.