I am looking for a gym floor cover that tennis can be played on.

You can put our Gym Floor Covers down to protect your gym floor and also play tennis on. You will need to secure the covers to the subfloor so that they do not move. The best way to do this would be to cover your gym floor with and underlay, and then place the gym floor cover over top of that. You can adhere the gym floor cover with double sided tape or a pressure sensitive adhesive.