If you fail a NSW security literacy test at SECTA, the first step would be to identify the areas where you need improvement. You may request feedback from the SECTA assessor on the areas where you scored low and use this feedback to guide your study and preparation for a future test.
You can also consider seeking additional resources or training to improve your security knowledge. There are many online courses, books, and other materials available that can help you to develop a better understanding of security concepts and best practices.
Additionally, it may be helpful to review the test format and familiarize yourself with the types of questions asked so that you are better prepared for the next test.

It is important to remember that failing a security literacy test at SECTA is not uncommon, and it is an opportunity to learn and improve your knowledge.
With persistence and dedication, you can work towards achieving a passing score on future tests.