Backup & Recovery :: RMAN Backup Multiple Retention

I am designing the scripts for RMAN backup.

Currently we have 14 days retention policy for daily and weekly backup. but we will have 186days retention for monthly backup, that's mean its should be recoverable around that 3 month (for monthly).

My question is, What should I put the scripts for monthly backup ?

I saw some example its for offline backup:

BACKUP DATABASE UNTIL 'SYSDATE+365' NOLOGS;

But I want the backup should be online ?

Currently our weekly backup like this

#!/bin/bash
# SID= env | grep ORACLE_SID | cut -c12-15
export ORACLE_HOME=/oracle/BWD/112_64
export ORACLE_SID=BWD
LOGFILE=/tmp/BWD-weekly-`date +%y%m%d%H%M`.out
[code].......

And Daily backup:

#!/bin/bash

SID=EPD
export ORACLE_HOME=/oracle/$SID/112_64
export ORACLE_SID=$SID
#LOGFILE=/tmp/EPD-weekly-`date +%y%m%d%H%M`.out
LOGFILE=/tmp/$SID-daily-`date +%y%m%d%H%M`.out
echo>> $LOGFILE
[code]......