Because you will not yet have NEET Roll no#, you can fill in the column with your NEET registration number. Against NEET Registration number column as well, please fill it up with your NEET registration number. That is absolutely fine. To help you with your NEET preparation, we have NEET Knockout packages that you can check at: https://learn.careers360.com/knockout-neet-may/. To help you during admission and counselling, we have https://www.careers360.com/mbbs-companion.