The Below query To check FRA Used Space and Free Space its very Useful Query :

set lines 100
col name format a60
select name
, floor(space_limit / 1024 / 1024) "Size MB"
, ceil(space_used  / 1024 / 1024) "Used MB"
from v$recovery_file_dest
order by name
/ 

Thank you
Osama mustafa