How to list files in oracle backupset
Try "List Backup", or perhaps "list backup summary"

http://docs.oracle.com/cd/E11882_01/backup.112/e10642/rcmreprt.htm#BRADV89586

and

http://docs.oracle.com/cd/E11882_01/backup.112/e10643/rcmsynta027.htm#RCMRF132