
Yes, typically you have scenarios that use these Objects or you can create your own scenarios and use them there. Some mod developers also put them in their own scenarios. Best is if you read the description of the mods.
In case your mod is a scenario, just put it either in the game's folder or in your AppData folder (you can go there by typing "%APPDATA%\Clonk Rage" in the address bar of explorer or simply press [Win]+R and type it in there) and start it in Clonk Rage. It will appear in the main menu if you click on "Start Game". (maybe just scroll down a little bit)
In case your mod is an object, make a scenario and put it in there as you want it. Just make sure the definition is loaded. To do so, either drag and drop the .c4d file into your scenario in the editor (which is probably the easier way), or make sure the checkbox in front of the .c4d file is checked and rightclick on your scenario, click on Presets, then choose "Local and preset definitions" and click on "Use current selection as preset". You can also do that by editing the Scenario.txt file in the scenario. Please refer here on how to do this:
https://crdocs.clonkspot.org/en/sdk/scenario/scenario.html (see section [Definitions])
Anyway, if you get a scenario with your mod, just put it in your game's folder and it will be there when you click on "Start Game".