rman target /

RMAN> list backup summary;
List of Backups
===============
Key     TY LV S Device Type Completion Time #Pieces #Copies Compressed Tag
------- -- -- - ----------- --------------- ------- ------- ---------- ---
590     B  F  A DISK        15-JAN-21       1       1       YES        TAG20210115T030004
591     B  F  A DISK        15-JAN-21       1       1       YES        TAG20210115T030004
592     B  F  A DISK        15-JAN-21       1       1       YES        TAG20210115T030004
595     B  A  A DISK        15-JAN-21       1       1       YES        TAG20210115T041934
596     B  A  A DISK        15-JAN-21       1       1       YES        TAG20210115T041934

RMAN> delete backupset tag 'TAG20210115T030004';

using channel ORA_DISK_1

List of Backup Pieces
BP Key  BS Key  Pc# Cp# Status      Device Type Piece Name
------- ------- --- --- ----------- ----------- ----------
590     590     1   1   AVAILABLE   DISK        /oracle/backup/rman/database-20210115-j0vklj9l_1_1
591     591     1   1   AVAILABLE   DISK        /oracle/backup/rman/database-20210115-ivvklj9l_1_1
592     592     1   1   AVAILABLE   DISK        /oracle/backup/rman/database-20210115-iuvklj9l_1_1

Do you really want to delete the above objects (enter YES or NO)? yes
deleted backup piece
backup piece handle=/oracle/backup/rman/database-20210115-j0vklj9l_1_1 RECID=590 STAMP=1061866805 deleted backup piece
backup piece handle=/oracle/backup/rman/database-20210115-ivvklj9l_1_1 RECID=591 STAMP=1061866805 deleted backup piece
backup piece handle=/oracle/backup/rman/database-20210115-iuvklj9l_1_1 RECID=592 STAMP=1061866805 Deleted 3 objects