Given this information, OP's current performance is on track with an ATAR of approximately 90-91. The fact that OP is taking 13 units means that his lowest-performing 3 units will not count towards their ATAR. These can be a combination of any of the following subjects, which appear to be his lowest-performing subjects:
- Mathematics Extension 1
- Mathematics Advanced
- Chemistry
- Physics
Because only 3 units of the above subjects can be disregarded, OP will still need to thoroughly prepare for the HSC exam of these subjects to ensure that whichever of these subjects ends up counting towards his ATAR makes a positive contribution and maximise his chances of achieving his ATAR goal.
On the other hand, Biology is OP's best-performing subject due to his optimal rank. Being ranked first is important, especially if OP also manages to score the highest HSC exam mark in his cohort. In such a case, the moderation process would work in his favour, as his overall HSC mark would be made equal to his HSC exam mark, essentially allowing him to maximise his result for this subject, resulting in a greater contribution to his ATAR.
OP's performance in PDHPE and English Advanced is also good, though perhaps at a slightly lower standard than Biology. This can indicate some areas of improvement that OP can focus on addressing as part of his preparations for his HSC exams, enabling him to ensure favourable results in both subjects.
I hope this helps!