Any chip is a defect that you must decide if its ok or not. Generally, if its not too large, and has no other spiders comming out of it, its safe. Trying to tell yes or no from a photo is pretty hard.
I would pass on buying any tank with that kind of physical damage .... unless the seller is giving it to you. If you already owned the tank and we’re asking whether it’d be safe to run it’d be a different question.