Hello Aspirant

Any mistake that you made while filling the application form can e rectified during the correction period except for your category and nationality.

So, yes you can select aptitude once the correction process begins, just make sure to rectify all mistakes in your form before the correction window closes, because after the correction period gets over you won't be able to make any changes in your form you will have to continue with those details only.

You will be notified about the schedule of Correction window on your registered mobile number and registered email id.

Hope this helps