As far as this year, admission in NIFT does not consider 12th board marks. The process is based upon the NIFT entrance exam which are held differently for different streams. So, how much you score in 12th won't matter as long as you have passed. You will only have to meet the entrance cut off.
Hope this helps!
Based on your 12th you can apply for various designing courses in NIFT. The eligibility varies for all courses.
Minimum percentage required is not mentioned as such rest you can check the detailed criteria in the link below:
NIFT Courses & Eligibility Criteria