Given this information, I believe that your performance is consistent with an ATAR of at least 98 and up to 99.5. Your performance is evidently excellent across your subjects, meaning that all your subjects are highly likely to make a positive contribution to your ATAR. From this point, your goal is to prepare for your HSC exams to the best of your ability so that you can hopefully maintain this standard of performance and achieve your ATAR goal. Depending on your circumstances (only you know where your areas of improvement are best), you may wish to consider putting in slightly more effort in terms of for your preparations for your Mathematics Extension 2 HSC exam, as that could enable you to maximise your overall result in this subject.
Of course, this information assumes that you are a year 12 student. However, you have 2024 as your HSC year. If you are in year 11, this information would still be relevant since it provides an indication of your performance potential in year 12, which is clearly high in your case. You should therefore maintain your effective study strategy going forward and ensure that you address any potential areas of improvement along the way, should they arise.
I hope this helps!
