Excause me Symantec Employee but your wrong
Please turn to page 86 of your OpsCenter admin guides and read along
"OpsCenter Server and Agent are installed on OpsCenterHost 1, NetBackup 6.5
master server is installed on , and ProdHost 1 another NetBackup 6.5 master
server is installed on ProdHost 2.
You need to install NetBackup 6.5 Remote Admin Console or master server on
OpsCenterHost 1 and configure two data collectors, one to collect data from
ProdHost 1 and another to collect data from ProdHost 2."
Also search that doc for "remote agent" it'll tell you what you where asking MEM.
Basically you need to install an Agent somewhere, on that same box install Netbackup 6.5 Remote admin tools. Then point opscenter to it in the Agents tab.
Done.