CJI: how is it implemented on a preferential basis?

State of Punjab : suppose there are 10 vacancies for SC in a particular recruitment, 5 were reserved for Mazhabis and valmikis if they were available and if they were not available it would go to the other SCs like ramdasias etc... this preference based reservation was not at anybody's cost. If they could not make the cut off , a SC would only get it would be converted to general, those vacancies would then be carried forward etc. If you cannot give as much as preference to the needy without being at the cost of somebody and that Act of the state govt is what is correct , we urge that