I have a Rodecaster PRO and Windows with Audition. Rodacaster PRO is set to multi channel. I start a multichannel session in Audition. (now the problem) I only can choose voor 2 mics in Input. What is the problem?
You need to use the Rodecaster Pro ASIO interface, otherwise you'll only ever get the two default channels. You download it from Rode, install it and then select it in the Device Class entry in Preferences>Audio Hardware.
I added the ASIO interface by downloading it from Rode's site. I selected ASIO in the preferences. It added all the channels but I'm not getting any levels when I speak in to the mic.
Need more information about exactly what you are doing - with some screengrabs, probably. You do need to allocate channels specifically to tracks before you'll get anything happening though...