Hi Vijay, first off, if you're using JON you can directly open support cases for any issues you have.
The way the server installation works is that it starts up a "vanilla" EAP Server and then the installer modifies it to be a JON server. For some reason the initial EAP server startup is either failing or is not accessible to the installer. Check the rhq-server/logs/server.log for any indication as to what may be wrong. There are other logs there as well but the server.log may indicate the startup issue. Typically this kind of issue is due to a host address issue, like a resolution problem.