att galaxy note 3 usable in south korea??

i heard something about regional lock on galaxy note 3. And I was wondering even if this was true, can i still use the note 3 in south korea by flashing att note 3 with ROM of one of south korean carrier(such as SKT)?? The hardware is pretty much the same right?? after flashing to native korean ROM, i would be able to use it as if I bought it from korea??