So I was just wondering. I have been using mirc to chat on port 6667 and I have been banned from internet usage for a short period of time. Now I know that residents use aim and msn messenger freely, so I was wondering if I was to change the port from 6667 to 5190(aim's), if that would solve the problem. I'm guessing that my university monitors the common ports for mirc and that's how it catches violators

Would this work, or am I completely wrong?

You can only connect to an IRC server using the ports that the server has open, which for IRC, 6660-6669, 7000 are the most common. So unless your IRC server is listening on port 5190 for client connections, no it won't work.

~ Edit ~
If you are caught circumventing network security, you could be banned permanently or worse. You really should consider just waiting out the ban.