Running a Concurrent Program Against a Specific RAC Instance when Parallel Concurrent Processing (PCP) is enabled is introduced in Oracle Apps Release 12.1, it doesn’t work in 11i.
Note: If an instance specification is made for a concurrent program and the instance is up, it will be picked up by the first manager available to run it and the manager will run the request in the specified instance; however, if the target RAC instance is down, the manager will run the request in the instance where it is already connected and log an appropriate message.
To achieve this navigate through System Administrator Responsibility > Concurrent > Program > Define > Click ‘Session Control’
‘Target Instance’ applies to concurrent programs. This means although Concurrent Manager is connected to a different instance, the request will be run on a specific instance which is directed by ‘Target Instance’ parameter.