Hi,
To become an ips officer you have to clear upsc exam , it is one of the most difficult exams in the country. And if you clear this exam you will definately become a high rank police officer .
After 12 you have to complete graduation from a recognized college and then you can apply for upsc exam .
Age criteria -
Candidate must have attained the age of 21 years as on 1st august of the year in which the exam will be held. The upper age limit of the exam is 32 years.
Upsc exam is conducted in three stages - prelims ,mains and interview and one has to clear all of these to get a post.
Hope it helps..

The Indian Police Service (IPS) is one of the three All India Services of the Government of India. This post is very great. To became an IPS you have two modes. Students are recruited from any one of these two.

• Promotion of SP Service officers
• Giving UPSC exam

The exam consists of three parts.

1. Civil Services (Preliminary) Exam
2. Civil Services (Main) Exam
3. UPSC Personality Test / Interview

Also there is some eligibility for becoming an IPS. Check the details below.

1. Candidate must be an Indian Citizen
2. Age Limit – Minimum age of 21 years, maximum age varies.
3. Candidate must be a Graduate from a recognised university

For this firstly you have to get admission in some college to get a graduate degree . And for UPSC exam you can start your preparation from your 2nd or 3rd year in college. Also you can take coaching from some good coaching institute.

Hope this helps!