If you haven't been initiated, you are allowed to join another NPC sorority.

The "wait one year" rule applies only if you'll be re-rushing at the same campus.

Keep in mind that you'll have to rush one more time and several factors can play a role on whether or not you'll receive a bid -- how competitive is rush at your new school? Your class standing and transfer status? Your grades? All stuff to keep in mind.

ETA: LOL, I guess we all posted around the same time.