I have moved your post from NetBackup forum to Infoscale forum.
Infoscale is the new name for Storage Foundation and Veritas Cluster family group.
The Storage Foundation and Veritas Cluster forums also still exist in this community: https://vox.veritas.com/t5/Business-Continuity/ct-p/business-continuity
About your upgrade query:
If you have a valid Entitlement (document received from Veritas with new purchase or maintenance renewal), then you can download new license key and software from Veritas Support site.
Logon to https://www.veritas.com/support/en_US.html
Select Licensing, then Entitlements.
A list of your company's Entitlements will appear.
If your email address was not provided with purchase order, then you need to find out who's email address was supplied.
This person will need to logon to access license keys and software downloads.
For Veritas products guides, please go to https://sort.veritas.com/documents then select products, OS, lanuguages etc accordinngly. Veritas user guides are in .pdf format.
For upgrade related info, just download and view product release notes and installation guide of the versions you plan to upgrade to.