Also operating system compatibility for snapshot client is available on below mentioned link.
http://seer.entsupport.symantec.com/docs/303344.htm
Just for your information Flash Backup applies only to Enterprise Server.
Use for the policies that contain only NBU flashbackup clients on UNIX. This policy is available only when the NBU Snapshot client is installed.
For more information on configuring such policy you can refer to the
Snapshot Client Administrator's Guide