Hi, since you have 257 marks in SC category rank in NEET exam so below there are some colleges mentioned  by my side on which you may have your eye there once, I hope it will help you;

• Maulana Azad Institute of Dental Sciences, New Delhi
• Seth GS Medical College, Mumbai
• Institute of Medical Sciences, Varanasi
• Stanley Medical College, Chennai
• Government Medical College, Nagpur
• Government Medical College, Surat
• SMS Medical College, Jaipur

Etc.

Moreover you can also visit on the below link to predict your college by your own on behalf of the the rank you have got(link mentioned below):-

https://medicine.careers360. com/neet-college-predictor? icn=QnA&ici=qna_answer

Good Luck.