Dear Anita,

The eligibility criteria for the NEST 2019 exam is as follows -

The candidate should have passed their 10 + 2 exam in either 2017 or 2018 or will be passing in 2019. Education Qualification - The candidate should have at least 60% in aggregate in their 10 + 2. SC / ST / PWD candidates at eligible at 55% only. 

General and OBC category applicants born on or after 1st August 1999 are eligible to apply for NEST 2019 are eligible for the exam.

So, if your 12th passing year is 2017 or more you are eligible.

Hope this helps.

Good luck!