257 in Neet is not an appropriate score to get a college through All India quota. Through all India quota the cutoffs are usually higher and that is why any score at least less than 550 out of 720 is less. Even for Dental, you need to secure at least 500 marks in Neet for a SC category candidate. However you can try for state counselling as for state quota candidates the cutoffs are comparatively low and the private medical colleges participate in state counselling so you have chances to get seat in private medical colleges. In your profile it shows you belong to Andhra Pradesh and going by last year's cutoffs, 434 was the lowest cutoff for Sidhhartha Medical College. To get complete list of colleges you can based on your rank use this link http://medicine.careers360.com/neet-college-predictor?icn=QnA&ici=qna_answer