About primary server upgrades
Upgrade NetBackup on the primary server before you upgrade NetBackup on any other computers in your environment. Once the primary server upgrade is finished, you can upgrade media servers, and then clients. NetBackup supports a mixed version environment. More information about this topic is available.
See About compatibility between NetBackup versions.
Two primary server upgrade methods are supported: either the NetBackup upgrade script or the native UNIX and Linux installers. The NetBackup upgrade script is the standard upgrade method and is recommended for new users. The native UNIX and Linux installers are potentially more difficult and require additional steps.
NetBackup includes UI for all the supported versions of NetBackup. More information about supported versions of NetBackup is available.
https://sort.veritas.com/netbackup/eosl
Note:
It is recommended that after you install or upgrade NetBackup server software, you uninstall older versions of the Remote Administration Console (Windows and Java) present on the host. If the native NetBackup Administration Console for Windows is present, it is automatically uninstalled when you install or upgrade the NetBackup server software.
See About compatibility between NetBackup versions.
Proceed with the upgrade.