How to check the Locked tables

If you want check the Locked tables execute the below query

SELECT oracle_username os_user_name,
       owner,
       locked_mode,
       object_name,
       object_type
         FROM v$locked_object lo, dba_objects do
 WHERE lo.object_id = do.object_id;

Output:-
OS_USER_NAME,OWNER,LOCKED_MODE,OBJECT_NAME,OBJECT_TYPE
APPS,APPLSYS,3,FND_CONCURRENT_QUEUES,TABLE
APPS,APPLSYS,3,FND_CONCURRENT_REQUESTS,TABLE
APPS,INV,3,MTL_SYSTEM_ITEMS_INTERFACE,TABLE
APPS,INV,3,MTL_SYSTEM_ITEMS_INTERFACE,TABLE
APPS,INV,3,MTL_ITEM_REVISIONS_INTERFACE,TABLE
APPS,INV,3,MTL_ITEM_REVISIONS_INTERFACE,TABLE