First make registration on RH customer portal (https://access.redhat.com/home
), so you will be able download 30-day evaluation version. Install ant try it (points 2-5 by Pingu). Purchase a license and subscription if you want. But I also suggest to try first CentOS. Prior to purchase visit Red Hat's Customer Portal with information about the subscriptions, levels of support, hours of coverage, severity levels and response times for Self-Support subscription, Standard Subscription and Premium Subscription. Not all forms of support are available in all location of the world.