Considering this information, your current performance appears to be consistent with an ATAR in the low 80s range. More specifically, that would be an ATAR of approximately 83-84.
Physics is your best-performing subject, and is likely to make a positive contribution to your ATAR. Despite this, there may be room for improvement in this subject. If that is the case, you should capitalise on this opportunity by thoroughly preparing for your Physics HSC exam, allowing you to ensure favourable overall performance, and consequently maximise this subject's contribution to your ATAR.
The same can be suggested, although to a lesser extent, about your position in most of your subjects. Specifically, there are likely areas of improvement in English Advanced, Mathematics Advanced, Engineering Studies and Business Studies. Focusing on addressing these as you continue to prepare for your HSC exams will help you do better in your HSC exams, allowing you to improve your overall performance and thus maximise your chances of reaching an 85+ ATAR.
On the other hand, it seems that Mathematics Extension 1 is your lowest-performing subject. If it ends up being your lowest-performing subject, it will not count towards your ATAR since you are taking 11 units. However, it is still worth thoroughly preparing for this subject, because improvements to your overall performance can enable a significant contribution to your ATAR from this subject specifically.
I hope this helps!