What is the weighting that your remaining school-based assessment tasks/exams will contribute across your subjects? The higher this percentage, the greater your opportunity to maximise your rank if you are able to perform at a higher standard in your upcoming tasks.
I think that this is an interesting situation. Your ranks in Mathematics Advanced and (potentially) Software Design and Development appear to be favourable, which would likely mean that your current performance in both subjects is consistent with your desired ATAR. Because of this, you should ensure that you do your utmost to maintain this standard and, if possible, improve, because the higher your rank, the more likely you will be to maximise your Assessment Mark.
On the other hand, your position in Biology, Physics and Mathematics Extension 1 is concerning. While favourable results in Mathematics Advanced and SDD would definitely increase your chances of achieving an ATAR of 85, this can be negated by unfavourable performance in those other subjects. It is therefore important to try your best to address areas of improvement in each subject which, alongside more extensive preparation, will hopefully allow you to improve your rank by performing well in your next tasks.
I see no mention of English, although your post indicates that your rank in English is also not great, which means that the above advice would also apply here.
With that being said, your ATAR goal is still within reach. This is not only because you can still improve your performance in your remaining internal tasks, but also because the HSC exam itself is very important, as it contributes 50% of your HSC mark for each of your subjects, making your HSC exams another great opportunity for you to complete your comeback and maximise your chances of achieving your ATAR goal.
I hope this helps!