Loading the V-Ray Plugin in Cinema 4D
Default
When using the default installation method, V-Ray is installed in the Cinema 4D plugins folder. This means that the V-Ray plugin is loaded automatically when Cinema is started. In this case, all you need to do to start rendering with V-Ray is to change the Render Engine to V-Ray in the Render Settings.
You can adjust some of the additional V-Ray settings in the Preferences menu.
Custom
You can set a custom location for the V-Ray plugin directory when opting for the Advanced installation method. In this case, you need to manually locate the V-Ray plugin to load it in Cinema 4D. To do so, go to Edit > Preferences... to open the preferences menu. Open the Plugins tab. There, click on the Add Folder... button and locate the folder in which you have installed the V-Ray plugin. The directories must match so Cinema can find the V-Ray plugin. In the screenshot, you can see the directory set for the V-Ray plugin during the installation matches the directory for the plugin search path.