You need to have some sort of balance you can't study 24/7 everyday for the 6 weeks. What I suggest would be to do around 4-6 hours (has to be time you are focused in and not procrastinating) worth of study each day. In this time you should go back over the first topic you have learnt at school and ensure your notes are updated and better than before. Then after this I would encourage for subjects where you can make notes try do the next two or three topics in the holidays. You don't have to understand every single dot point, so if you are unsure about a dot point and what it means leave it and revisit later when you learn it at school, or learn the whole course as the person above has suggested in that time, because the issue is if you do subjects such as physics and chemistry it will be particularly difficult for you to master everything by yourself with no help or teaching from your tutors or school teachers. For English, this is tricky to try do yourself cause specific modules and essays require you to do different types of things that you sort of need assistance from a teacher or tutor to tell you what these are, but you can always just read or watch the texts and compile some sort of basic document with quotes and techniques, that you can later use to make an essay once you start that topic at school. For other subjects such as maths try to learn ahead I.e. just go through a textbook and complete questions within it so you understand the fundamentals before you go to school.
In terms of how you should structure your studying. I would recommend you do it in like blocks of one hour separated with breaks where you can do whatever you want in like play games or look at memes lol. A timetable may be helpful but I don't think that should be your primary source of motivation, which should be the end goal the atar and your uni course selection. You should go on a word document or google document, then write down your subjects and what marks you are aiming for in the HSC and your atar aim. Stick these on a wall that you can always see and when you feel like bludging during those hour blocks that should be a good enough reminder for you that you need to work hard.