As long as you are interested in appearing for NEET and fulfil its criteria, you are eligible to appear for NEET. There is no holding you back there. But we will be honest with happens after you get a seat in the Counselling. Before that you will have to talk to your administration because you will need the Original documents for document verification, counselling and admission. MCC will have nothing to do with this. So it is your responsibility to get the documents and you will have to contact your Administration for that. Every college has its own rules pertaining to letting a student exit a seat midway so you need to talk to them.