257 marks was the least cutoff last year equivalent to an AIQ category rank of 7518 for sc category in Tamil Nadu state. The college with least cutoff was IRT Perundurai Medical College, Perundurai and you seem away from it. The cutoffs are expected to rise this high since you too might be knowing that the number of candidates had increased and also the paper level was called easy comparatively.. 

Either take a drop and comeback with better marks next year or else go for other courses like BAMS BHMS or BPT or BSC etc. 

For further detailed information refer to our site.. 

https://medicine.careers360.com/articles/neet-cutoff-tamil-nadu

Best wishes. 

Thank you.