The Fire and Restoration E-News drew my attention to to your post. Further to the information Greg provided above, you may need to seek an environmental approval to undertake the burning. The type of environmental approval that may be required depends on whether the burning you plan to conduct is for bush fire hazard reduction or whether it is for another purpose.
Another consideration is that in many council areas, particularly metropolitan areas burning vegetation is prohibited under the Protection of Environmental Operations (Clean Air) Regulation 2010, except with an approval from the NSW Environment Protection Authority and/ or the Council. It might also be a good idea to contact the local council to enquire how they have been identified in the regulation.
The NSW Rural Fire Service have published a document titled Before you light that fire. It provides a guide for the ins and outs of the approval processes and what steps and legislation applies in certain circumstances.