Hello aspirant,

The Combines Defence Services Examination(CDS exam) includes the following and their eligibility ages vary accordingly:

1. Indian Naval Academy (INA)---------->19 to 22 years
2. Air Force Academy----------------------->19 to 23 years
3. Indian Military Academy (IMA)------->19 to 24 years
4. Officer's Training Academy ----------->19 to 25 years

The above mentioned are the caders and their respective age limits.  As you have mentioned your exact day, month and year of your birth, lets see the valid time period within which you could take your CDS examination.  For a candidate who was born on 12 January 2004 the age limits are as follows:

1. Indian Naval Academy (INA)-------->01 Jan 2024 to 01 Jan 2027
2. Air Force Academy--------------------->01 Jan 2024 to 01 Jan 2028
3. Indian Military Academy (IMA)----->01 Jan 2024 to 01 Jan 2029
4. Officer's Training Academy --------->01 Jan 2024 to 01 Jan 2030

The above mentioned are the ranges within which you can take your CDS examination.  Also, double check your eligibility from their official website(upsc.gov.in  -->check in the what's new section of the webpage) before applying for the examination.

To know more details about the examination, to know the important dates, syllabus and for previous year's question paper, visit the following link:

https://competition.careers360.com/articles/cds-application-form

Hope it helps, All the Best for your Examination.

Thanks..!