You guys have 5 native turtle species- the Sydney basin turtle (Emydura macquarii), Snake necked turtle (Chelodina longicollis). Less common is the Northern snapping turtle (Elseya dentata), Broad shelled turtle (Chelodina expansa) and the Mary river turtle (Elusor macrurus). You will need a Licence in NSW and it is illegal to remove animals from the wild!
This should help you with what you need.
DECC | Complete outline of the NSW reptile licensing system (PDF - 117KB)