In Deployment Manager, there is General tab in "SITES" and you can change various Site properties as the guide mentions:
https://docs.tibco.com/pub/tdv/8.5.5/doc/html/en-US/DeployManHelp/index.html#page/DeploymentManagerHelp%2FCh_3_Using_deployMNGR.2.11.html%23
I would like to change the Site Name itself as well on that page.
Please find the attached screen shots.