In this scenario, if two users log in at the same time and the some state is store in bean then wouldn't there be a conflict or will each user have its own bean where some state/data could be kept for a while.
If there is a conflict then why should we use MVC pattern.
MVC pattern don't point that you use only single bean to store your state. There may be more that one bean instance created to store the state if required. The exact requirement depends on your application.