Convoy - you team up with ninja(AI) who will help you in battles (like Kakashi, Naruto, Choji)
Survive - You or your convoy ninja must not die during combat
Collect - you must collect something from the ground (ex: collect 0/5 scrolls)
Plot - no idea

Elite instances:
REC - recommended ninjas for your main (ex: If you are fire main your REC ninjas will be Ino-Shikamaru because they have good sinergy with your main)