Confirmed that VM backup was completed successfully, however got the below error message from vSphere Client:
"event.com.veritas.netbackup.backup.success.v2.fullFormat"
VMware vCenter 7.0
VMware vCenter 8.0
This event is generated through the API call from NetBackup onto the vSphere as an alert, however, this is not an error/failure but only a depiction of successful backup.
Refer to Veritas link:
https://www.veritas.com/support/en_US/article.100052656