I have registered for the neet 2020 but i want to change the option regarding ews Is it possible??

Hey,
Yes, Changing category is possible during the correction period. The correction window will be open from 15 January 2020 to 31 January 2020.
You can visit the official site during this time period, and you will find a direct link for application correction.
You can login with your user ID and password and then you can make the corrections needed.
But, this is a one-time correction window, so make sure you check everything properly before submitting the application. After submitting the application,you cannot change anything again.

All the best.
Hope this helps!!