A transfer from UTS Engineering to UTS IT would be done via UAC (
http://www.uac.edu.au/). This is because it is from a faculty to a different faculty.
In terms of marks and UAI, it will depend on the course. For example, the UAI cutoff for BScIT/DipITProfPrac in 2006 was around 80.00 and for BBus/BScIT it was around 84.00. If you got lower than that, a credit average+ would be desirable.
For more details I'd recommend emailing someone like John Colville (colville@it.uts.edu.au). Last year he was the Undergraduate Program Leader for the Faculty of IT. If he isn't anymore, then I'd ring up the IT student centre and see if I can talk to someone equivalent to that.
Good Luck!