Dear student

There might be technical issues that's why it's happening. As yesterday it was Sunday so technical team might be on holiday so they might have not been resolved the issue. You can try today in afternoon or evening hopefully it will get submitted.  Keep trying some times it's happen you should just try.

Sometimes the website is down due to the higher traffic of students trying to register at the same time. So, it would be better to wait a bit and then try to apply for the registration process.

For more information on expected colleges you can get on the basis of your NEET score, use this college predictor tool.

https://medicine.careers360.com/neet-college-predictor?icn=QnA&ici=qna_answer

I hope this answer resolves your query.

Good Luck!