If one is keeping archive logs available on disk and also have them archived to tape and would like to delete only the ones that have been archived to tape in the archive directory through RMAN, you can use the following command.

connect target /
connect catalog rmancatalog/rmancatalog@catalog;
# For Tape
run {
DELETE ARCHIVELOG LIKE '%' BACKED UP 1 TIMES TO DEVICE TYPE SBT_TAPE;
}

# For Disk
run {
DELETE ARCHIVELOG LIKE '%' BACKED UP 1 TIMES TO DEVICE TYPE DISK;
}

# Delete logs backed 2 times and more than 1/2 day old
run {
delete noprompt archivelog until time = 'sysdate-0.5' backed up 2 times to sbt ;
}