You can apply for anywhere you like. Whether you get it or not depends on whether or not said place recognises an Aussie licence at face value or requires you to undertake additional training. For instance, in the UK you would need to sit an Assessment of Prior Competence and then take whatever "differences" training is stipulated by the CAA. Apparently it's rarely much less than the full course these days, but I can't comment on that.
There's also local employment laws to take into account - the USA, for instance, will not take non-US citizens. In many countries also, ATCOs are civil servants which means taking the civil service exams (in their own language, of course!) first.
However, I know of Aussies controlling in
Ireland
Germany
ME
and IIRC Canada.
Pretty sure there's a couple in the UK too.
It would be worth sticking the same question on the Civiilair forum too.
Good luck!
ap