Hey.

The eligiblity criteria laid out for CDS 2020 exams states that the Candidate who applies must be atleast older than 19 years of age to be eligible. The age limit is supposed to be calculated as on January 01, 2020. The specified age limit it as follows.

For IMA – 19 years to 24 years

For AFA – 19 years to 23 years

For INA – 19 years to 22 years

For OTA – 19 years to 25 years

Considering this you seem to be only eligible for OTA and not for the rest.

Best of luck