My advice is that you should go to JYP first, coz as you've said, there're a lot of mixed races. So, even if you're not Korean, there's a high chance that you'll be accepted and train there, if you really have talents. If you failed the audition, don't give up your journey. Just look at AOA's Choa. She failed many auditions, and look at where she is now. You have my support anyways :D Good luck btw!