After creating the role in EM and restarting the services open RPD in online mode
Manage-->Identity Manager-->Action--> Synchronize Application Roles then it will reflect all roles which you are crated in the EM.
I did that, but could not able to see the newly created role. Predefined roles are visible only.
That's strange. Roles should be visible immediately after creation throughout all components.
What version are you on?
Did you run a wildcard query in the Admin Tool to search for the role explicitly or did you do it through a "Permissions" option on an object?
Can you see the Roles from the presentation catalog permissions interface?
I am able to see the created role in catalog permissions interface. I have run wildcard query in admin tool. But could not able to see the role which i have created. OBIEE version is 188.8.131.52.0.