Hi aspirant

Definitely you are eligible.

NATA takes entrance exam twice a year.You can appear in any one of them or both .It won't matter.

The eligibility criteria for NATA is as follows:

• Students who have passed class 12 with minimum 50% marks in Physics,Chemistry and Mathematics along with 50% marks in aggregate are eligible to appear in NATA.
• Candidate must have attained minimum age of 17 years as on July 1 on the year of admission.

Know more about NATA here: https://engineering.careers360.com/articles/nata-or-jee-main-paper-2-which-better-option-for-barch-admission

hope this helps you.