Hello how you can do a rollback to 9.2.1 to 9.0.2 and then I can be blunt iPad it? Through iTunes I could not do not allow help . 9.2.1 I have an old rebate
iPad 2, iOS 9.2.1
You can't. Apple does not, and never has, supported downgrading iOS.
There is no support nor procedures from Apple to be able to downgrade your iDevice to a lower iOS version.
Plus, Apple only signs the previous iOS version for a very short time and that time has long sinced past.
It would be better if you explain what issues you are having with your iPad 2 and the current iOS 9.2.1.
Recoil
