Salman, I get the impression that you're a 'doer' and not much of a 'reader'...?
The column heading says 'Start of Support'. That says to me that all subsequest versions are supported.
W.r.t. the 6.5.5 patch installation - the patch that you are trying to install is for a NBU Master or Media server.
Have you upgraded the Master and Media server(s) to 6.5.5 yet? This must be done before upgrading of clients.
Extract from 6.5.5 download URL:
http://seer.entsupport.symantec.com/docs/337041.htm
Under the
UNIX heading:
Note: NetBackup UNIX Add-on products and Database Agents have separate Release Updates.
NB_CLT_6.5.5.tar provides updates for NetBackup 6.5 for
all UNIX clients.
NB_6.5.5.rs6000.tar provides updates to NetBackup 6.5 on
AIX servers.
Under
UNIX Agents/Options heading:
6.5.5 Release Update did not refresh the packages below. The 6.5.4 packages can be used with 6.5.5 systems:
NB_ORA_6.5.4.tar provides updates to NetBackup 6.5 for
Oracle Database Agent on
UNIX platforms
Another extract:
For 6.5.5, some Agents/Options have not been updated with new code and are not distributed with this release update. These situations require the Agent/Option to fall back to the latest patch available if it is not available for 6.5.5. For example, a UNIX client running Oracle should be updated with the NetBackup 6.5.5 client package (NB_CLT_6.5.5.tar), but since there is no Oracle Agent update for 6.5.5, the 6.5.4 Oracle Agent update (NB_ORA_6.5.4.tar) is to be applied. The latest 6.5.x package is referenced in this document.
The 6.5 GA Release is the base 6.5 Server software that must be installed before patches/updates (6.5.x) can be installed.