Dear Sandeep,
I see that you are installing SecurityManager in your server. One of the errors you might be getting when you start your server is "java.net.SocketPermission". If this error is occuring, the reason is the SecurityManager is restricting your server to accept connections. To make it work, you can create your own policy file. Policy file is an ascii file containing all the permission you wish to grant to your server. Your policy file may look like this
grant {
permission java.net.SocketPermission "localhost", "connect,accept,listen,resolve";
};
If your create an ascii file called 'mypolicy' and put the above grant statement in it, then you can start your server like this
java -Djava.security.policy=mypolicy RMIImpl
The use of policy file will allow your server to accept connections.
You can learn more about policy file by going to the following URL
http://java.sun.com/products/jdk/1.2/docs/guide/security/permissions.html