Hello dear student, 

Greetings! 

According to CDS eligibility criteria:-

Candidates who have passed graduation or appearing for their final year are eligible to apply for CDS  exam provided they submit a relevant certificate of passing the examination at the time of commencement of course.

So you are eligible as you are in your final year. 

candidates applying for the exam must be 20 to 24 years. 

Thankyou