Hi ! To become a ips officer you must have a graduation at first .so my suggestion is that take admission in either IIT or at nit or at IIIT or at any GFTI. Then after graduation or completion of b.tech give government exams, UPSC, UPSC IPS ,and wbcs exam. Thus are exams through which you can be an iOS officer. There are other many exams and many ways but it will suit you. So hope you understand and best of luck to you.

Dear Gnaneshwar,

As per my knowledge you can't become an IPS officer right after 12th exam. First, you need to complete Graduation from a University/College and after completing that successfully you need to appear for Civil Services Exam and clear it.

Only after clearing the above you will be eligible to become an IPS officer. 

I hope i was able to help you with your problem,Good luck!