Is parking busines model of motorists legal in India

We are a Pvt Ltd firm building a parking app. Private parking contractors in cities often charge higher than govt mandated fees to motorists. While this is illegal there's next to no enforcement. We are creating an app where our users can get assured parking at higher than Govt mandated rates (eg fee of Rs. 30/hr for assured space in peak time as opposed to Rs 10/hr govt rate). The contractors cannot legally enter into this contract with the motorist but we can since we are not a govt contractor. We charge the Rs 10/hr as parking fee and the remaining Rs 20/ hr as convenience fee. On the convenience fee, we pay the applicable GST, and pay almost 80% back to the contractor as royalty for using our platform. Essentially, we become a channel where the contractors can get a higher price without breaking the law, and users can get assured availability at a premium. Does this model violate IPC or economic laws? Can we be held/shut down for propagating black marketing if we use this model?