Satellite 5.6 on RHEL 5.10

The documentation says that Satellite 5.6 will run on RHEL 5 but there is no ISO for Satellite 5.6 on a RHEL 5 server. I'm planning on upgrading to Satellite 5.6 but the base OS is RHEL 5.10, Is this possible or must I upgrade the OS to RHEL 6?