From 6.5 onwards you can use PureDisk in the following way.

1.  Use the PDDO option and backup your clients via NetBackup, but instead of using tape or VTL, it de-dups in the PureDisk storage pool.

2.  Use the PureDisk client to backup your clients to the PureDisk storage pool, and then export those backups to tape/VTL in NetBackup (from within PureDisk), so they are viewable as regular restores in NetBackup.