That depends on the subject and on what is considered a low mark according to you. However, I think it would generally be safe to assume that if a student performs in the way you are suggesting, they are likely not to receive a state rank for that subject. A student's chance of receiving a state rank also depends on Course Candidature and Maximum place in Top Achievers, as seen in the table below:Original Poster:
If your internals are low, however you smash the external hsc exam and get around mid to high 90s, do you have a chance of state ranking the subject?
I believe that for subjects like English Standard and Information Processes and Technology, receiving a state rank might be easier compared to other subjects as you may not be required to get extremely high marks (i.e. 95 and above) in order to receive a state rank.
To be more specific in terms of other subjects and with respect to the 2020 HSC, there is a person on here that came 9th in Mathematics Extension 1 with 100 as their final mark. That person also came 9th in Physics with a final mark of 97 and 19th in Chemistry with a final mark of 98.
I hope this helps!