Playing tug with a rope toy is not just fun, it can help to teach a puppy how to play appropriately, use up some of his excess energy and strengthen the bond with his human family. But a puppy's teeth are vulnerable and can be damaged with rough play.
Always play tug-of-war gently with a puppy, as his puppy teeth can be loose and his new teeth are still growing. Hold the rope toy to anchor it and let the puppy tug and pull on it. Just give an occasional gentle tug to make the game more fun for him. Never hold the toy up high so the puppy hangs on it, either as part of the game, or to get him to drop the toy, as this could hurt the puppy's mouth. He needs to learn to stop pulling and give up the toy when you ask for it.
To teach a puppy to stop pulling and leave the toy, have two tug toys -- a favorite and a less favorite -- and play for a few seconds with the less favorite one before bringing the toy towards your body. Hold a treat close to the puppy's nose, and as he lets go of the toy to eat the treat, give a voice cue, such as "drop," and praise him as you restart the game with his favorite toy. This way the puppy learns if he drops the toy, he gets a treat and a game with his favorite toy. Practice for a short time, but often, until the puppy lets go of the toy when he hears the voice cue.