If you’re at OCS, a request for a waiver will be sent to big NAMI (in Pensacola). You’ll continue to go through OCS while you wait, but typically you’ll either be advised by the flight doc to redesignate to a different community or not depending on what he/she thinks is likely to be waived.
As a side note, you are not officially NPQ from your original designator without the official NAMI letter saying you are, which you generally do not receive until you’re complete or near complete with OCS. With that said, even if the flight doc tells you to redesignate and you end up receiving a waver, you can keep your original designator - HOWEVER the opposite also applies where you can go through OCS and get NPQ’d at the end.
It sucks, and I’ve seen it happen. My advice if that happens to anyone is to make peace with getting another community if you’re serious about serving.