RMAN is hung or it is very slow / Clearing RMAN repository / Troubleshoot RMAN-06214 error

RMAN> DELETE FORCE NOPROMPT OBSOLETE DEVICE TYPE DISK;

If error still occurs, then try the below

RMAN> CROSSCHECK COPY OF CONTROLFILE;

rman> DELETE FORCE NOPROMPT OBSOLETE DEVICE TYPE SBT;
or
DELETE FORCE NOPROMPT OBSOLETE DEVICE TYPE DISK;

1) Cancel any Delete obsolete command sessions

2) RMAN> CROSSCHECK COPY OF CONTROLFILE;

3) Start the delete obsolete command with debug enabled to check whether RMAN is hung or it is very slow :

rman target / debug trace=debug.trc log=rman.log

RMAN> execute the backup script here

Upload to oracle, the debug.trc and rman.log for review.
Also upload the output of the below command :

RMAN> show all;