This is clear in the download page: http://www.jboss.org/products/eap/download/
To download JBoss EAP you must have an account. You also need to accept the terms and conditions of the JBoss Developer Program which provides $0 subscriptions for development use only. Read more about the JBoss Developer Program.
To run EAP on production you need a subscription purchased from Red Hat, that not only gives you access to the bug fix / security patches / enhancements (for example, 6.4.1 which will be released in near future) , but also entitles you to get technical support (web ticket, telephone, etc., depending on what subscription you purchase), and also, access to a great amount of online document / solution articles.
Simply give a call to RH sales team and find out the best option for you : http://www.redhat.com/en/about/contact
Alternatively you can choose upstream projects (JBoss AS 7 or WildFly) at no cost (no subscription needed)