Hello Sai Kiran, 

NATA qualification marks is subject to yearly change. As per 2018 trends, to qualify NATA the candidate has to score at least 25% in the MCQ section and 25% in the drawing section. Last year the overall minimum qualification marks for NATA was 80/200, that is, a score of 40 %. This year's cut off has not yet been declared and will be declared post exam. 

Hope this helps :)