Tenants have to pay to use Gym

I live in a building where the society has made a rule that the tenants have to pay 1k per month for 1 member to use the apartments gym. I am hearing this for the first time anywhere and my owner have no clue about this. Even the trainer at gym is saying it's not right to charge. Have anyone of you seen this in mumbai and why do they do that. Please enlighten me.