A interesting observation.....if a passenger books from Tata to Chennai in tatkal,there are 16 seats available in 3AC and 36 in sleeper class. But if he books from Rourkela the number of seat options increases . It becomes 16 in 3AC and 36 in sleeper class if booked by 18189. If booked by 13351 the availability is 16 in 3AC and 173 in sleeper class. So passengers from Rourkela have total 32 seats in 3AC and 189 seats in sleeper class quota in tatkal hence are doubly benefited.Quite surprising that the originating stations are having lesser quota and an intermediate station where amalgamation of two trains happen is getting the most quota !!!