hello Jayshree,

Eligibility of NATA 2019 is required passes 10+2. and marks 

Minimum marks: The candidate must have scored minimum 50% marks in aggregate in physic, chemistry, and mathematics. Further, the candidate needs to score minimum 50% aggregate marks in the qualifying exam.

for more info about NATA 2019 and eligibility, check the given link-

https://engineering.careers360.com/articles/nata

thank you.

Hello,
The marks you have mentioned here are the marks scored by you in 10+2?

ELIGIBILITY:
All candidates who have passed 10+2 scheme of examination with 50% marks in Physics, Chemistry & Mathematics (individually) and also 50% marks in aggregate at 10+2 level examination and are desirous to apply for 1st year of 5-year B.Arch. degree course may appear for NATA 2019. Those appearing the 10+2 exam with PCM subjects in the current year may also provisionally appear in the exam, however, their result in NATA-2019 will be declared valid subject to fulfilling the above criteria. Please refer detailed eligibility criteria in NATA 2019 Brochure.

Also, A candidate can opt appear either for first test or Second Test or can chose to appear in both tests. First test will be held on 14th April and 2nd test is on 7th July 2019. However, in case a candidate appears in both tests the highest marks obtained in either of the two examinations would be awarded to him/ her as final marks.

I hope this helps you.
All the best !!