No, your NAPLAN results do not count towards your HSC results or your ATAR. The only factors that contribute to your HSC results and your ATAR are the Stage 6 subjects that you take and your performance in each of them.
With that being said, NAPLAN results are often considered when applying to a different school in terms of assessing your academic ability, alongside other elements, such as your school reports.
I hope this helps!
