If you already have an installation of Serena Business Manager to which you plan to add Serena Release Control, you do not need to install a new system for Serena Release Manager. You do need to do the following:
Ensure that you are running a supported version of SBM as indicated in the Serena Release Manager Readme.
After installing the rest of the products in the suite, follow the post-installation system configuration instructions for SBM.
Please continue to Installing Serena Release Control.