Iphone 4s Jailbroken update?

We have tmobile so my dad bought an iPhone 4s and got it jailbroken. So today he updates it and now we're scared that his phone may not work. Right now it says that it needs to be connected to itunes but I'm not home and my computer is broken.

You would need to connect it to itunes and set it up
phone will work if it was working before after it was jailbroken

If its a factory unlocked iphone 4 updated to ios 6, it will be find, just no jailbreak.
if it was a software unlock, it will be locked back to att.