Hey!

To join CBI,first you have to join civil services by giving UPSC and become an IAS/IPS. Then it gives you opportunity to join IB or CBI as a subinspector by clearing SSC CGL exam for which you must have minimum 50% in undergraduation degree. This will open your path for CBI joining . And the salary of CBI director is around 80,000INR per month.

Thank you