if you are taking about collage or university no he can't as a failed refugee.
if you read his work permit it says "not authorized to take any collage or university programs"
plus even if they do allow it he has to pay over double the fees for collage or university. that was the reason I couldn't attend university or collage otherwise I would have had couple of degrees myself.
I remember when I attended collage through work (short collage program) the immigration contacted my school and mentioned to school I'm not allowed to take the program but since the company I worked at took full responsibility for the cost and everything they let me finish the course. it really isn't a good feeling not be allowed to go to school but unfortunately thats how it is with a failed refugee status.
I would suggest if you guys have already applied for your application just wait for your first stage (aip) which could take few month or up to 8 months. that way he would be allowed to go to school and the costs would be like a Canadian resident, because even if he applies under international student he would be paying over double the cost for programs.
good luck.
Thats also true....i also replied to you in the other thread where u asked the same question..ove there i ment high school courses..it also works for taking single courses at college or university...