what if i scored good %ile in JEE Mains (AIR 10,000) and got 56% in 12th Boards will NIT accept that in any round of councelling ?

It is difficult  to get seat in NITS but you can apply for good private universities or institutes who are taking their own entrance exam and having their own admission criteria like:

SHIVNADAR UNIVERSITY

NORTHCAP UNIVERSITY

MANIPAL INSTITUTE OF TECHNOLOGY

BENNET UNIVERSITY

IILM UNIVERSITY,GURUGRAM

LOVELY PROFESSIONAL UNIVERSITY

BML MUNJAL UNIVERSITY

AMITY UNIVERSITY

SRM UNIVERSITY etc

You can also try for state level counselling for engineering admission.

IILM UNIVERSITY,GURUGRAM is offering B.tech in computer Science and Information Technology with contemporary computing areas like:

Cloud Computing

Artificial Intelligence (AI)

Big data

Internet of Things (IoT)

Machine Learning

Deep Learning

Image processing

Block Chain

you will need at least 75% in boards to eligible for NITs