You haven't mentioned his Category. This is important because every Category has different cut offs. With a score of 450, his rank might be approximately between 82216-89872. This is an expected rank range: https://medicine.careers360.com/articles/neet-result-marks-vs-rank . The chances for Management seat depend on the State your son belongs to. For complete list of colleges that you may have a shot at, please use our College predictor: https://medicine.careers360.com/neet-college-predictor?icn=QnA&ici=qna_answer