I agree with the other posters. I know plenty of people who didn't complete year 12, yet have still been successful. My own brother didn't even finish year 10, then spent 3 years refusing to even work. But now he owns his own business & is in the process of buying his first home.

I suggest not letting him leave school without something else lined up. Find out what he's into & enrol him in a tafe course. Or send him out looking for an apprenticeship, or even just unpaid work experience, doing something he is interested in. He could do a 3 day tafe course & 2 days work experience. Maybe its mechanics, or panel beating? Graphics design? The things that interest him everyday are what he should try find something in. He may not make a career out of it, but it might keep him interested enough & get him at least in the door. Then if he decides to go further, he can get advise as to what to do next, as well as a reference from the employer.

My BIL will be 18 in January. He had all intentions of finishing year 12, but dropped out this year (11). He worked at Macca's for a few months last year, but he had no interest in that & hated every minute. He now has an apprenticeship at some metal work company I think. He's been there for a good few months & is very happy there