tub shower wall install

Hi guys I got a quick question abut the bathroom i'm redoing. I"M just about finished installing durorock in my tub shower, now my question is I plan to use Redgard as a waterproofer membrain, do i use thinset or mastic for the 6x6 porcelen tiles? right now its studs-durorock-regard-thin set tiles right?

thanks for the help