Airservices Australia Psychometric Testing
History suggests that previous international recruits have not all been successful (anecdotally ~60% pass...I hear that a while ago one US ex-regional tower controller was expected to rate on procedural enroute...)
My point being, have a backup plan. If you are a current ATC, don't burn your bridges, and if you don't have very recent experience I'd say you are probably unlikely to be offered employment anyway.
Just saying, :-)