This topic would help the one who faces either “iPhone is Disabled” or “iPad is Disabled” issues.
The following will give an instruction to Troubleshoot “iPhone is Disabled” Error using iCloud. It must work on iPad as well.
Access icloud.com/#find and sign in to your iCloud account.
In next step, you have to click on All Devices at the top.
Then select the device you want to erase.
Click on the “Erase iPhone” button. This will erase all the data which contains passcode lock on your iPhone or iPad.
After your device has been erased, you have the option to restore it with a backup or set it up as a new device without iPhone is Disabled problem.
If this solution does not work, there must be another way to solve the issue by using iTunes.