Hey Nijiya.

While filling up the NATA examination form remember you were asked to fill up a region in your state wherein you'd prefer to answer the exam, and if the center exists youll automatically be alloted to that center. Say for eg. you are from Goa and you have choosed to answer from Goa itself , selected center for Goa is Panjim and youll be automatically alloted that center.

You can go on official website and check for the centers of different states .

Have a Good day..