Hi Anurag,
I hope I can explain what you want to know... So if you want to use a session bean (stateless or stateful) you usually request an instance of this bean from the EJB container either by looking it up via JNDI or with annotations and dependency injection. If a bean with this lookup name exists you'll get an instance of that bean from the container.
STATELESS session beans are managed in a pool and you can't expect to get a specific instance because all stateless session beans are reused between all clients.
If you request a STATEFUL session bean the EJB container establishes a session which is specific to exactly one client. Unfortunately I can't find any detailed information on how the container determines what a "client" is in this context. Anyway the container creates a session and an instance of the stateful session bean which is given to the client. And the same client within the same session always gets the one and only single instance of a stateful session bean. So a value x=10 in bean A will still be there in a subsequent request from the same client in the same session.
If I understand your question correctly you want to know if a second bean B of the same class as bean A would have the same value x=10?!? But this is something which will never happen. If you use a stateful session bean and you once have established a session you will always get the same single instance of this bean from the container. So the container simply wouldn't create two instances A and B of a stateful bean of the same class for the same client.
Is it that you wanted to know? If not just let me know and I'll try to give you more information
Marco