You have a few options. You could repeat the HSC again which I am gathering is not your plan, OR you could do non award study. This means you study in a uni for a year. You get results in those courses that meet the requirements to get into a course and then apply through the University. The courses you have completed however only allow you into a course and do not allow you to apply for credit transfers etc.
You could alternatively go to TAFE and get some sort of certificate that allows you to get into university.
Or you could do one of the designed programs that universitys offer to allow you to enter uni.
For example- Newcastle's Newstep program.
I hope that helps you in some way. Good luck!! :wave: