Drop database using RMAN

For this, we, first need to connect to the target database and mount (NOT OPEN), enable restricted mode. Following are the rman commands:

RMAN> startup force mount;
RMAN> sql 'alter system enable restricted session';
RMAN> drop database including backups noprompt;

This will remove all datafiles, online redo logs, archived redo logs and control files, backup sets, image copies without any prompts.