No, you can't lol since your in year 11. you could if you were a accelerated student in a particular HSC subject. Speak to your teachers if your really good at your subject then my may allow you to sit the HSC exam only for that subject and then next year you don't need to sit that exam. make sure you ask this lol do not forget.
good luck lol and please don't start it again and don;t waste your valuable time. I suggest you should study and work hard instead lol.
