To be eligible for NDA, you should be between 16.5-19.5 years. For being eligible for NDA 2022, you should have been born between July 2nd 2003  to July 1st, 2006. This is for NDA 1. For NDA 2, you should have been born between January 2nd 2004 and January 1st, 2007. Going by this, if you were born on December 18th 2003, you are only eligible for NDA 1 of 2022.  By 2023 NDA 1, you already cross 19.5 years and so are technically not eligible for NDA 1 of 2023.