how to access the user account in the client machine, which are created from d server
 

I am new in linux and i have a doubt. In windows plateform on the client machine the user can login which are already created user account from the server . like that we can create a user in server(redhat) and how can i access that user account from the client machine.

well you're massively over simplifying a client and a serer there, but presuming you mean you use Active Directory then you can make a domain controller solution using samba and openldap. Alternatively there are many other simpler methods for centralized authentication, my choice of which would be openldap by itself.