Hi Amirtharaj,
the rmiregistry tool is indeed a simple
JNDI service provider. It's probably not as powerful as "real" JNDI services with LDAP backend or something like this but according to Sun it at least offers the JNDI interfaces.
Generally I think there's no problem to run rmiregistry in parallel to JBoss on the same computer. But by default they both use TCP port 1099 for JNDI lookups. So you would have to use another port for at least one of them. With rmiregistry the port to use is simply the first and only command line parameter to it. For JBoss I don't know where to change this. And of course you'll have to change your lookup code in clients to reflect the different port(s)
Marco