I have a z30 and it's unlocked from a carrier in Canada and now it's with att I have a att sim card

I need help

Will I get 10.3.1 on my unlocked z30

Yes. You can wait for Att or jus put another carriers sim in to do the update. If you have a canadian sim, or a european one, you should be able to update over wifi. The sim does not have to be registered. Or take the sim out and update via BlackBerry Link.

PassportSQW100-1/10.3.1.2243 O2 UK

I have a att sim card