OTOY offers a fully functional demo of OctaneRender. It is time-limited (usually 30 days) and watermarks renders. Crucially, it is and legal.
Before installing, ensure your hardware meets the necessary specifications to run both programs smoothly. Minimum Specifications Octane Render Cinema 4d R26 Free Download
The legitimate cost of OctaneRender starts at less than for a monthly subscription. Most professional 3D artists earn that back in less than an hour of work. If you’re a student or hobbyist, consider using the free trial, or explore free GPU renderers like Blender’s Cycles X (which is also excellent and 100% free). OTOY offers a fully functional demo of OctaneRender