Here is the guide to the legal method: The Legal Solution: Cinema 4D Demo Mode Maxon offers a full-featured trial of Cinema 4D. While it is technically a "Trial," it allows you to use the software without a paid license for a limited time. Independence Day 1996 Internet Archive Direct
However, there is a to use Cinema 4D that essentially functions as a "portable" version because it does not require a standard license key or permanent installation. Maria Hermie Nipple 2021 - 3.79.94.248
A direct search for a "free license portable" version of Cinema 4D typically leads to illegal cracked software, which is unsafe and against the terms of service of Maxon (the developer).