The C++ runtime is free to use in any application. I assume that is what you're talking about here. VC++ 6 however is a development tool and isn't free to use. It also is no longer supported anyway.
Please provide links and information on exactly what you're trying to do. If you need to develop C++ programs then you need to be looking at Visual Studio 2022. It is not free to use in enterprises (or any company for that matter). There is a Community Edition available but it is free for open source, students and hobbyists. It is not free for use in building commercial software.