You haven't mentioned the State and Category you belong to. This is important because AIQ and State Quota has different cut offs for various Categories. With a score of 636, your rank might be approximately between 1900-3000. This is an expected rank range: https://medicine.careers360.com/articles/neet-result-marks-vs-rank . Now regarding the Colleges that you may have a shot at, we will need your Category. But to speak in General, you have a chance in:

• Dr, BabaSahib Ambedkar Medical College
• Hamdard Institute of Medical Sciences

Now HIMS is a Deemed University. Now this is based on 2019 data and cut offs change every year. Cut offs change every year depending on various factors such as no.of Candidates appearing for the exam, no.of Candidates qualified, top NEET score and difficulty of the exam. For complete list of colleges that you may have a shot at, please use our College predictor: https://medicine.careers360.com/neet-college-predictor?