Hi,

As per the official notification, for Ground branch Candidate must be born between 1 January, 1996 to 1 January 2002. For flying branch, candidates must be born between 1 January 1998 to 1 January 2002. You have mentioned that your age is more than 23, but not have specified the number. If your age is between 20-24 then only you can appear for AFCAT. During the time of joining, candidates must be 24 or less. Maybe during the training time you will exceed the age limit that may be the reason for non-eligibility. You can look for ground duty.

Check the official notification and other information over here: https://news.careers360.com/afcat-2021-application-form-released-afcatcdacin