dear seema,

In this situation you have you have two options -

1. if you filled some details incorrect in your neet application form then after closing of applications you have chance to correct your details in between 15 jan 2020 to 31jan 2020.
2. you can apply your application form again by using another email id and mobile number then you get the new registration number and proceed forward.                                                                                                             In my opinion you should go for second option because you said that you haven't submitted the application form.