This is not allowed (EJB prohibits concurrent access to bean instances).
You could try to re-design your solution, maybe add an extra layer.
then what is the use of retrieving EJBObject from the SessionContext object. I think weblogic server allows concurrent calls to stateful bean. Does jboss doesn't support or it is not allowed at all. I am new to ejb please give me clear information.
Its an EJB spec thing menaing its by default not allowed by any app server. Any client can have any number of EJBs references. Any single EJB instance can never accept concurrent calls to its business methods.
You are talking about the EJBObject from SessionContext in the tricky sequence :
EJB A -> EJB B -> EJB A
There are other cases when you want to pass a reference as a method argument or result.