The only approved method for rolling back a patch is to restore the database and applications to a restore point taken immediately before the patch. If the patch is small enough, like only a few reports or pl/sql objects, you may be able to restore them, but this will not correct your file or patch history.
I do not want to restore but i am trying to find out the purpose of backup directory.
If there is any option that provided by oracle to rollback the patch using this backup directory.
I normally purge the backup directories to reclaim space before patches are deleted. There are no methods for rolling back a patch in 11i/R12 apart from restoring from a fill backup.
How to uninstall backout rollback an Oracle Applications 11i or R12 Patch (Doc ID 343987.1)