The mc6 file is created by saving a Material Collection in the Material Room. Applying this to your figure will load the textures for whatever material zones you selected when you saved it (the default being all zones for the figure), and the pz2 Pose file will do the same thing.

"If I were a shadow, I know I wouldn't like to be half of what I should be."
Mr Otsuka, the old black tomcat in Kafka on the Shore (Haruki Murakami)