Flash_Recovery_Area

SELECT 
    NAME, 
    TO_CHAR(SPACE_LIMIT, '999,999,999,999') AS SPACE_LIMIT,
    TO_CHAR(SPACE_LIMIT - SPACE_USED + SPACE_RECLAIMABLE, '999,999,999,999')
       AS SPACE_AVAILABLE,
    ROUND((SPACE_USED - SPACE_RECLAIMABLE)/SPACE_LIMIT * 100, 1)
       AS PERCENT_FULL
    FROM V$RECOVERY_FILE_DEST;

 There’s many scripts you can use to monitor FRA Or Arvhive I will post Few Of them :

Select file_type, percent_space_used from v$flash_recovery_area_usage;

SELECT NAME,
TO_CHAR(SPACE_LIMIT, '999,999,999,999') AS SPACE_LIMIT,
TO_CHAR(SPACE_LIMIT - SPACE_USED + SPACE_RECLAIMABLE, '999,999,999,999') AS SPACE_AVAILABLE,
ROUND((SPACE_USED - SPACE_RECLAIMABLE)/SPACE_LIMIT * 100, 1) AS PERCENT_FULL
FROM V$RECOVERY_FILE_DEST;

 Query the V$RECOVERY_FILE_DEST view to find out the current location, disk quota, space in use, space reclaimable by deleting files, and total number of files in the Flash Recovery Area. For example :

SQL> SELECT * FROM V$RECOVERY_FILE_DEST;

NAME                        SPACE_LIMIT SPACE_USED SPACE_RECLAIMABLE NUMBER_OF_FILES
----------- ---------- ----------------- ---------------
D:\Oracle\flash_recovery_area 838860800  292490752                 0              44

Query the V$FLASH_RECOVERY_AREA_USAGE view to find out the percentage of the total disk quota used by different types of files. Also, you can determine how much space for each type of file can be reclaimed by deleting files that are obsolete, redundant, or already backed up to tape. For example :

SELECT * FROM   V$FLASH_RECOVERY_AREA_USAGE;

FILE_TYPE    PERCENT_SPACE_USED PERCENT_SPACE_RECLAIMABLE NUMBER_OF_FILES
------------ ------------------ ------------------------- ---------------
CONTROLFILE                   0                         0               0
ONLINELOG                     2                         0              22
ARCHIVELOG                 4.05                      2.01              31
BACKUPPIECE                3.94                      3.86               8
IMAGECOPY                 15.64                     10.43              66
FLASHBACKLOG                .08                         0               1
 

You Can check 
Flash Recovery area – Space management Warning & Alerts [ID 305812.1]

 thank you
Osama Mustafa