The following are the commands you can type from the Rman prompt.

{
allocate
alter
backup
beginline
blockrecover
catalog
change
connect
copy
create
crosscheck
configure
duplicate
debug
delete
drop
exit
endinline
host
library
list
mount
open
print
quit
recover
register
release
replace
report
renormalize
reset
restore
resync
rman
run
rpctest
set
setlimit
sql
spool
startup
shutdown
send
show
test
upgrade
validate

Thanks