Hi,
for Aecop in March you have to apply first for eligibility. There are no deadlines for that, but according to when your application is considered eligible then you'll be allowed to do the exam. I reckon it's time for you to sent the documents now if you wanna do the March exam. Go to http://www.physiocouncil.com.au/ and you can read the official procedure. For help and more info and to talk to people involved in the process you can be part of our study group, but for that I need you to send me a Yahoo email address.
Hope this helps.
Emanuela