Hello Aspirant

If you have submitted your form successfully, then yes you can't make any changes in your application form until correction period begins.

After the correction window opens, you will be able to make certain changes in your application form. Also your category and nationality can't be changed once filled.

Make sure to correct the details in your form before the correction period is over, because after that you won't be able to make any changes.

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

Hope this helps.