Recovery With and Without a Recovery Catalog

When RMAN is connected to a recovery catalog, the recovery procedure with a backup control file is identical to recovery with a current control file. The RMAN metadata missing from the backup control file is available from the recovery catalog. The only exception is if the database name is not unique in the catalog, in which case you must use SET DBID command before restoring the control file.
If you are not using a recovery catalog, then you must restore your control file from an autobackup. To restore the control file from autobackup, the database must be in a NOMOUNT state.  you must first set the DBID for your database, and then use the RESTORE CONTROLFILE FROM AUTOBACKUP command.

Setting the DBID and Restoring the Control File from Autobackup

SET DBID 320066378;
RUN
{
  SET CONTROLFILE AUTOBACKUP FORMAT 
    FOR DEVICE TYPE DISK TO 'autobackup_format';
  RESTORE CONTROLFILE FROM AUTOBACKUP;
}

RMAN uses the autobackup format and DBID to determine where to hunt for the control file autobackup. If one is found, RMAN restores the control file to all control file locations listed in the CONTROL_FILES initialization parameter.