Assuming it hasn't changed over last few years - CNCC;
Could be Ric Halliwell you contact? Theres only a few permits per year (2or3?) given out on set-dates only, so I guess if a lot of clubs request one they may go into a hat??
I think the Craven Pothole Club have historically been most involved in the exploration of Robinsons. Since Ric Halliwell is a CPC member, I am sure he is a good person to ask about the situation.