Everything you need to know to make the best California rolls: Perfect sushi rice, dips, sauces and secret techniques! A full step-by-step photo tutorial! -love california rolls, not so much sushi though.
In my opinion cup should be + cup or cup + 2 Tbsp, but 6 Tbsp is the same as both of my options too. I would just go with the simplest conversion, taking two measurements cup and cup) is easier and less time consuming than measuring out 6 tablespoons.