Given this information, your current performance seems to be on track with an ATAR in the mid to high 80s range, that is, an ATAR between 85 and 88.5. This essentially means that your ATAR goal is within reach, subject to favourable HSC exam performance, ideally across your subjects.
Mathematics Extension 2 is your best-performing subject, meaning that it is likely to make a positive contribution to your ATAR. It is therefore important to thoroughly prepare for this subject's HSC exam, allowing you to maintain this level of performance.
Though not unfavourable, your performance in Mathematics Extension 1 and English Standard is of a lower standard, which indicates that there are areas of improvement which, if addressed, can help you perform better in your HSC exams, bringing you closer to your ATAR goal. This can be achieved by focusing more of your efforts towards preparing for these two subjects.
On the other hand, Chemistry and Physics are your lowest-performing subjects. This means that the contribution of each subject to your ATAR at this stage is likely the worst compared to the rest of your subjects. Further, these are likely the subjects where there is the greatest room for improvement, based on which you may wish to consider emphasising these subjects as you continue to prepare for your HSC exams.
I hope this helps!