The examination for recruitment of candidates in the Indian Police is conducted by union public service commission every year.
As per the union public service commission's guidelines, one must be graduate, in any discipline, to be eligible for the exam.
The minimum eligible age is 21 years and the maximum age limit is 30 years.
The maximum age limit, is however, relaxed for candidates belonging to OBC category and SC/ST category.
The examination is usually known as civil service exam and comprise of two written exams and an interview. One must qualify all the stages to be considered for the Indian Police Service.
For more information, refer to the official website of UPSC.