Hello

Once the test centres are allotted you are not allowed to change the test centres. If you get a tset centre whuch was not in your preference list it was because you filled the form a bit late and the seats in that centre got filled by the time you chose those centres.

You cannot change the exam centre after the release of admit card. I advise you to try to think of ways in which you canreach the allotted examc entre to give the exam. All the best!