TO CHECK THE LOCKS FOR A PARTICULAR CONCURRENT PROGRAM OR REQUEST

select * from v$session where process in(select os_process_id from fnd_concurrent_requests where request_id='<Req Id>')

from this u will get SID
take that sid and find object_id's from below command
select * from v$locked_objects where session_id='SID'
now take all the object_id's and check any other session is locking those object_ids apart from the above SID...
select * from v$locked_objects where object_id =''
if any session is locking check the status of that session from v$session.
if that is inactive kill that session ... to free up the resource