Hey Sankalp

You will get a choice for ve preferred cities where you wish to write the aptitude test while completing the online application form.  No request for the change in the exam centre will be entertained after filling the form.

However if the examination is not possible to be conducted in any of the centres due to unforeseen reasons, the candidate would be allotted an alternate centre, and such information will be communicated in due time.

For more queries you can write to IISER at  ask-jac2020[AT]iisertvm.ac.in

All the best.