Free tick by tick data means that currently what NSE charges Rs 1lk/year for TBT data when on colocation, will be free. This makes no material impact in terms of costing as the real expense is the cost of being colocated itself. Can cost tens of lakhs.
Also TBT data feed can’t be streamed to clients, you have to be colocated to consume because of the sheer amounts of data. Whatever small benefit this has, will be only to traders/brokers who have their own setup within NSE colocation.