Hi Adam, Thanks for your reply.
I have checked the wiki and the video and followed steps to create Organization.
I have created a non-admin user and assigned in to one branch of an Organization.
Created a Mashup and set visibility of the Mashup at the route level of Organization.
Branch with non-admin user has got no visibility for the Mashup.
Then I tried to launch the Mashup using the non-admin user.
I was expecting that the Mashup will not be visible because the user didn't have access.
Where as the opposite happened.