Now we know that NTA will not communicate with us through offline mode. All the communication is done through the email id and mobile number that you registered for NEET exam. If you have entered them wrong, you cannot get any communication from NT regarding Admit card, etc. That is a problem. But if you gave the correct mobile number then the login details should be there and you can use them. You cannot take a direct print out of your admit card from your mail. You have to download it and take a print out directly from the website only. As the counselling also is online, then you may face issues. But for now if you gave correct mobile number you are safe. Wrong email id will not affect the exam. It affects the other process.