A total fire ban means no fires outside, except in very limited cases
http://www.rfs.nsw.gov.au/fire-informat ... -ban-rules So if staying in a camping area with gas barbeques cooking may be allowed on them but not your own burner. There may also be park fire bans which allow using your own gas burner under certain conditions.
There usually aren't a lot of total fire ban days but park fire bans are more common, and some parks may have fires banned for the summer.
The best idea is to allow for this with some main meals that don't need cooking, or picking something up in a town.