EAP 5.1.x is based on "JBoss AS 5.1.0.GA" (community version). You can download EAP 6.x from Red Hat JBoss Enterprise Application Platform Download | Red Hat Developers which is enterprise version of JBoss. For further support on JBoss EAP, you'd need subscription.
Thanks for the information.
How i can check whether my JBoss 5.1.0.GA which is installed in our environment is licensed enterprise version or community edition.
How i can upgrade JBoss from 5.1.0.GA to jboss-eap-6.3.0(which i downloaded from the above link).
Check boot.log file and look for line like below:
20:39:37,946 INFO [ServerImpl] Release ID: JBoss [EAP] 5.1.0 (build: SVNTag=JBPAPP_5_1_0 date=201009150028)
If boot.log shows "Release ID" with JBoss [EAP], then its enterprise version of JBoss.
You can follow to migration guide https://access.redhat.com/documentation/en-US/JBoss_Enterprise_Application_Platform/6/pdf/Migration_Guide/JBoss_Enterpri… or How do I migrate my application from AS5 or AS6 to AS7 - JBoss AS 7.1 - Project Documentation Editor