Can I still apply if I decide to take a gap year?

FAQ topic: 
About the Application Process

Yes. If you take a gap year you can still apply for a Co-op Scholarship when applications open again the year after you complete your HSC. However, if you are not 100% certain that you will take a gap year, we would encourage you to apply the year you complete your HSC. If you later decide to take a gap year, you cannot defer a scholarship offer, but can reapply* in the next round.

(See: Can I defer my UNSW Co-op Program Scholarship?)

* Please note that if you commence a university degree or undertake any university study towards a degree during your gap year you will become ineligible for a Co-op Scholarship. Some exemptions apply, e.g. accelerated high school subjects including HS1917, studying at a yeshiva, etc.