No, there is no version of MP3 Rocket listed on the main website compatible with the Windows Vista OS. The only thing you can do is to run the software in compatibility mode, but I don't see why the software won't work on Vista if it supports Windows 7.
Typically, apps made for Windows 7 are compatible with Windows Vista as well. Download the installer, right click it and go to Properties > Compatibility. Pick something like Windows XP and run it or simply use Run as Administrator on the installer and then follow the installation procedure.