If you need multiband compression without the cost of the C6, consider these highly-rated free VSTs: Kilohearts Essentials
Waves offers a Free Plugin Pack that includes essential tools used by top producers.
is a paid product, there are legitimate ways to get it or similar "exclusive" free alternatives. Waves C6 Multiband Compressor Features
None of these include a “C6 Stereo.”
If you want the "exclusive" feel without the legal risk, these three plugins are currently the top free stereo multiband tools available in 2025:
