For UPSC NDA and NA (Naval Academy) Ist 2020 Recruitment, a total of 418 seats have been provisionally announced out of which, 370 seats are for NDA (Army-208, Navy-42, Air-120 (28 for Ground Duties)) and 48 for NA.
Based on the last year cutoffs, a candidate needs to score a total of around 704+ marks out of 1800 including both, the written exam and final stage SSB interview with atleast 342+ (25%) marks out of 900 in the written exam. But it is likely to increase this year.
For further details related to the last year cutoffs, kindly visit : https://news.careers360.com/nda-1-2019-cutoff-and-recommendation-details-released-447-candidate-recommended
Hope it helps you.