Open the administrator console. Under NetBackup Management, expand (click on the +) the group for host properties, and then click on clients. Scroll down to the host name in the list in the right pane and left-click on the name and wait.
What I have found when doing upgrades recently is that what is in the version file is the major version of 6.5 not any patch versions. When clicking on the name in the client list, I get the correct major and patch revision for that client.
If it still has issues, try to doing a /usr/openv/netbackup/bin/install_client_files command with the proper security and host names for that client. It will force the master to push over the updated client files accordingly, assuming that the master was setup to retain all the client install files.