Given this information, your current performance seems consistent with an ATAR between 96.5 and 98. It is normal for different estimates to report differing possible ATARs or ATAR ranges, since they may be done differently.
Your position is favourable across your subjects, although the degree to which it is is not the same. Mathematics Extension 1 is your highest-performing subject, meaning that it will likely make a highly positive contribution towards your ATAR. Because of this, you must ensure that you maintain your excellent performance in this subject, allowing you to retain your rank, which would place you in a comfortable position as you approach your Mathematics Extension 1 HSC exam.
The same can be suggested, although to a slightly lower extent, about your performance in English Advanced and Chemistry. This means that both subjects are also likely to make a positive contribution towards your ATAR, although not at the level of Mathematics Extension 1. Maintaining (and if possible, improving) your position in both subjects would increase your chances of a higher ATAR.
While your performance is not of a low standard in Mathematics Extension 2 and Physics, it appears to be the lowest compared to the rest of your subjects. This indicates that the most improvement can be made in these two subjects (of course, you know your own strengths and weaknesses best). Based on this, you must do your utmost to perform at the highest possible standard in both subjects, which will hopefully bring you closer to your ATAR goal.
I hope this helps!
