Dear Diksha

If you are seeking admission on a general category seat, then under state quota with 320 marks, it might prove difficult for you to get MBBS in Assam Medical College. Last year, the lowest marks to get admission in Assam medical College was 447 under state quota (general category). But, every year the cutoffs score keeps changing depending upon the availability of seats, the number of aspirants, difficulty level of exam, etc. Given that MBBS seats have increased this year and as per experts the NEET 2018 was difficult than its predecessors, changes are likely. 

You might find more information on the state-wise cutoff of NEET 2018 in the article given below. 

NEET 2018 section-wise analysis and state-wise cutoff

Hope it helps! 
All the best!