The last candidate to get a Government college in SC category through All India Quota of NEET 2017 secured a NEET Rank of 52,996. The candidate obtained 442 marks out of 720 and was allotted Thoothukudi Medical College, Thoothukudi. So if the trends for NEET 2017 remain the same as this year, then a score of 442+ should suffice in getting a Government medical college through SC category under All India Quota. However, it is always best to aim higher as cut offs always vary from year to year. 

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For getting a seat in a government medical college, you should have a score of atleast 450 if you belong to the SC/ST category. All the colleges will have different cut-offs depending upon the domicile state, so 450 is the minimum that you should be scoring to get a seat.