Master Download list: http://www.symantec.com/docs/TECH65429

extract:

6.0 Release Updates
6.0 MPx Release Updates requires 6.0 GA/6.0 MP4 installation media be installed before installation.  For customers in need of 6.0 GA/6.0 MP4 installation media, go to:
  http://www.symantec.com/docs/TECH63533

TECH63533 tells you this:

Download locations:
   * Symantec File Connect:    http://fileconnect.symantec.com 
 
Symantec FileConnect - List of Available Products:    http://www.symantec.com/downloads/fileconnect/index.jsp 
      This index is arranged by
                      * Product family
                      * Within each product family, by language. 

A serial number is required to initiate the software download through FileConnect.   This serial number is specific to the FileConnect site and is not the product license key.  The serial number will either come with an upgrade or purchase letter.

You will need to download 'Options and Agents for Unix' from FileConnect.

Installation and config instructions in NBU for Oracle Admin Guide.
Links to all NBU 6.0 manuals: http://www.symantec.com/docs/TECH50517 

PS: PLEASE convince Solaris 9 sysadmin to upgrade to upgrade to supported Solaris version. You find yourself without any support on this OS and NBU 6.x.