Whether this type of restore is supported by VMware, I don't know.
Using NBU - not possible with version 8.0.
vSphere 6.7 update 3 is only supported as from NBU 8.1.1.
Please see NBU 8.x OS SCL:
@pats_729 Thank you for replying. The VM was backed up when it was on vSphere 6.5 U2 (same version of esxi hosts). The VM environment is now on vSphere 6.7 U3 (same version of esxi hosts) to which we want to restore the VM from backup. If I read your reply correctly,seems only way this restore is possible is if we have an esxi host running 6.5 U2.
The issue at play here is that the VDDK version used by NetBackup 8.0 is not supported by vSphere 6.7 U3 (this is a VMware support issue not strictly a NetBackup one). As others have said give it a try and see if it works.
From my point of view the concern is that you are using an unsupported configuration for your current backups - NetBackup 8.0 is not supported backing up a vSphere 6.7 environment as per our (and VMware's) compatibility list. If you run into problems, I have a feeling that you would be on your own to solve them. Of course if you aren't protecting your VMware environment with NetBackup anymore, then that's a different matter.
Back to your original question - restoring a backup taken with NBU 8.0 on vSphere 6.5, to a supported NBU version with vSphere 6.7 U3 should be okay - the key here is using a supported NBU version.