Can you give us an example? Like if you say the teacher is mean towards a kid(or even a group of kids) he/she could just not like that kid(or group of kids) for example in my math class their is a group of kids(all black) that our teacher can't stand...but he's married to a black women and fine with most other black students...so if your accusing the teacher if being racist make sure he/she acts racist towards ALL students of that race.
You could try, firstly, bringing the issue to a principal. If you're making such an accusation, however, you will need examples of the behaviour and resources to back you up. Else, there isn't much they can or will do.
prinicple, counciler, dean, any one whos higher in authority then the teacher.
u should talk to the guidance counselor .. maybe even your parents..
You talk to the principal.