Am I eligible for IAS exam after completing BCA?

CBI recruits candidates through direct recruitment, deputation, promotion by seniority or through Limited Departmental Competitive Examination. All direct recruitment of Group C posts for sub-inspectors, constables and lower division clerk are made through Staff Selection Commission (SSC). Procedure

Yes, any Bachelor's degree in any subject with a third division is the minimum requirement to appear for IAS exam. Even, you can choose any optional subject of your choice for the Mains exam.