After completing 12th examination , you are not eligible to apply for CDS Examination because it is graduate level examination . If you want to give the CDS Exam then first you have to complete your UG degree.

CDS stands for Combined Defense Service

A candidate should have completed their graduation with atleast 50% from recognized universities

You should have a nationality of INDIA.

Age Limit:

for Indian Military Academy : 19-24 Years
for Air Force Academy : 19-23 Years
for Naval Academy : 19-22 Years
for Officers’ Training Academy :19-25 Years.

CDS exam has three wings

Indian Military Academy

Indian Air force

Navy

ELIGIBILITY CRITERIA:

Indian Military Academy:

You should be a citizen of india.
Your age should be between 19 to 24 years.
You should have degree from a recognized university.
Only unmarried male candidates are eligible. Girls are not eligible.

Indian Air force:

You should be citizen of india.

The age limit should be between 19 to 24 years.
You should complete graduation from any recognized university.
Only unmarried male candidates are eligible.
You should have physics and mathematics at 12th standarde compulsory.

Navy:

You should be a citizen of india.
Your age limit should be 19 to 23 years.
You should have degree or B.sc from a recognized university.
Only unmarried male candidates are eligible.