Dear Uday, NEET score is valid for 1 year if you plan on pursuing Medicine in India and 3 years if you plan on pursuing Medicine abroad. It isn't clear as why you did not take admission in a Medical college if you cracked NEET but if you want to study MBBS in India, this year the admissions have closed and the classes have commenced. You will have to appear for NEET next year again and appear for counselling. If you get a seat, you current University, you have to inform your current University and take admission in the Medical College.