I honestly didn't have many extra curricular involvements. Only had representative swimming, tennis, and martial arts outside of school.
Zero involvement with any leadership stuff, no duke of ed, no public speaking, no volunteering, no music, no school clubs.
As for my report: maths, English, science and commerce were 90+ I think, and the rest were hovering around 80.
Honestly it could swing both ways. You don't need the best marks if you have god tier extra curricular involvements, nor do you need any extra curricular if you have pretty solid academics.
The best thing you can do is focus on the exam and prepare for the interview. If you don't make it in this round, try a little harder with marks, especially maths and English, and pick up a couple extra curricular things. Also, teachers' comments on your report may play a considerable part, so account for that too.
Feel free to DM me if anyone reading this wants to chat more about it. (Moved from normanhurst to ruse in yr 11 for reference)