"...
Licensing BMR on a UNIX or Linux system
The BMR master server is installed when you install the NetBackup master server.
No separate installation is required.
However, you must enter a license key to
activate BMR and then create the BMR database.
Your license key may be a single key for the base NetBackup product and all
NetBackup add-ons that you install, including BMR. Alternatively, you may have
a separate license key specifically for the BMR option.
If you entered your BMR license key when you installed NetBackup, BMR was
activated then. If not, use the following procedure to enter a license key.
In a cluster environment, license theBMRmaster server on all nodes in the cluster
that host a NetBackup master server.
To verify if a BMR license key was entered previously, perform the following
procedure and list the license keys already entered.
To license BMR on a UNIX or Linux system
1 Log on as the root user on the system on which the NetBackup master server
is installed.
2 Enter the following command to list and add keys:
/usr/openv/netbackup/bin/admincmd/get_license_key
..."
and further:
"...
Licensing the BMR master server on a Windows system
The BMR master server is installed when you install the NetBackup master server.
No separate installation is required. However,
you must enter a license key to
activate the BMR master server and then set up the BMR database.
..."
It's not a separately purchased option, although it was a few versions back, hence the 'confusion' (even in the guides!) regarding licensing. So maybe your base license includes BMR?
For reference:
Listing of Symantec NetBackup (tm) 7.0 Manuals