Want to become CBI Officer, how to

I want to become Central Bureau of Investigation officer, please provide eligibility???

[Quick Sam]

To become a Central Bureau of Investigation officer, you have to appear in the exam which is conducted by UPSC.
That exam is Combined Graduate Level Examination.

The exam is conducted once a year for the post of Sub-Inspectors of Police in Central Bureau of Investigation.

Eligibility
The eligibility criterion is graduation with 50 per cent marks.

Age of the candidate should not exceed 25 years.

Exam pattern
The Scheme of the Examination will be conducted in three Tiers.

Written test
Interview
Medical Test

They are Written Examination, which is a Objective Multiple Choice Type, Main Written Examination which is also Objective Multiple Choice Type and Personality Test /Interview or Skill Test.

The Candidates who chose post of Sub-Inspector in CPOs will have to undergo Physical Endurance Test (PET)/ Medical Examination after declaration of result of Tier I.

The paper in examination consists of following sections:

General Intelligence Reasoning
General Awareness
Numerical Aptitude
English Comprehension