Dear Pulkit, the exam cities are given on first cum first serve basis. So even if you have prioritised few cities as your cities of preference, if by the time you have selected and completed the application form if someone else has filled up these places, those Candidates will be given priority. And the authorities always mention that mere selection of cities doesnt guarantee that you will get your exam city of your choice. To be honest, there is nothing that you can do about it.