Hello,
Unfortunately, CMC Vellore does not provide any corrections or change window. If a student makes a mistake then the only option is to fill a new form and make another payment. I don't think so your mistake will be a big issue and will make any problem. As both the city and district will be same so it doesn't matter in your case. To be on the safer side, I would suggest you to contact the office to confirm for the same.
Regular exam updates, QnA, Predictors, College Applications & E-books now on your Mobile