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.