Dear Satyam 

Yes, you will be eligible to appear in both NEET and AIIMS MBBS 2020, as the minimum age requirement for both the exams is 17 years of age (by December 2020), and with your birth date, you will complete 17 years in April 2020. 

This matrix is when we go by present rules of both NEET and AIIMS MBBS, and in all probabilities, they should remain the same. 

Hope it answers. 

All the best!