The rule SG9 states that only one cone can be possessed unless stacked on a mobile goal. My question is if there is a stack of cones on a mobile goal being carried by a robot, is it allowed to support the cones either from the side or else from the top?
Yes, this is legal. However, these Cones will not count for points at the end of the match unless the Robot removes its support from the stack. Please see this Q&A for further clarification which will be included in the August 17th final manual update.