Have you merged the patch as per instructions ?
Error is consistent with the upgrade steps.
Please find below R12.2 upgrade release notes for your reference.
Oracle E-Business Suite Release Notes, Release 12.2 (Doc ID 1320300.1)
The minimum AD Patchset level is R12.AD.C before you can try to perform R12.2 upgrade that is the reason your patch is failing.
You are on lower baseline release R12.AD.B which is not supported for R12.2 upgrade thus the error.
I would strongly recommend to review the notes and include latest recommended patches as per the upgrade guide.
Good Luck !