According to NATA eligble criteria every candidate have to passed or appearing 10+2 with 50% marks and mathematics as a compulsory subject... Fpr complete details you can check this link

https://engineering.careers360.com/articles/nata-eligibility-criteria

Yes you are eligibile. According to NATA eligibility criteria, a candidate must have passed or is appearing for the 10+2 with 50 % marks and mathematics must be a compulsory subject. Please go through NATA 2018 Eligibility for full details.