Can the property sue the gym? Is it legal?

Yes, it's legal. If there is a dispute between the property company and the gym and communication fails, you can bring a lawsuit to the court for settlement. According to the provisions of Article 123 of the Civil Procedure Law of People's Republic of China (PRC), the people's court shall protect the parties' right to sue in accordance with the law, and the lawsuit that conforms to the provisions of Article 119 of this law must be accepted, so it is legal for the property to sue the gym. Gym refers to a place for fitness, rehabilitation and exercise activities.