The Aurora Australis is only visible from the southern latitudes and is very unlikely to be seen north of the 30 degree line of latitude.
The aurora is associated with solar wind activity and is most prevalent at the peak of the eleven year sun spot cycles, and the three years afterwards.
The best places to see an Aurora Australis in the Australasia region would be Tasmania or New Zealand, away from cities and other sources of artificial light pollution. The following website, http://www.spaceweather.com/
, allows you to see on each day the current area that aurora can be seen.