I just got my letter today saying my audition for music school on december the 11th and want me to have 3 pieces that show a range of styles and im not sure what to do I mainly play metal but have touched on some other styles before.

By the way this not your berkle kind of college like you have overseas its a small place in new zealand and its just certificate so i can learn more about music so the standerds on only having jazz and classical pieces with sheet music are not as important.
Give the school a phone call is best bet, ask to talk about the audition with HOD or a tutor or to a current student there. They won't bite.
Is it popular music based? Is so probably a ballad, a dance piece and or pieces from differing decades would do.
Its a certificate in comtempery music so i don't think ill do a dance piece I was wondering if I should bother doing a jazz and classical piece because I don't really play them thats what im going there to learn.
Well, at least classical is self contained, you won't need a tape or accompaniment, but you will need the technique and stylistic awareness.
Really you ought to approach the school, your teacher or your school's music dept for advice. You haven't much time. I can recommend classical teachers in Ak if you need help in that dept.
ok Ill give a the school a call, i got a classical piece now i can play now i no most of it so ill finsh learning it this month and im just gonna use two of my own songs I wrote but i can't and don't sing but they said you have something or someone to play along with you.

Thanks for the help
You really need to call them to find out what, exactly they will accept. You'd really hate to rely on the advice of folks here who know nothing about the school, and then fail because of it. There are no re-writes. If you bomb it, you're out of the running for another whole year.

Could I get some more talent in the monitors, please?

I know it sounds crazy, but try to learn to inhale your voice. www.thebelcantotechnique.com

Chris is the king of relating music things to other objects in real life.