04 November 2007
Indian Revenue Service (IRS) belongs to Group A Central Services of India.
Selection is through the Civil Services Examination conducted by Union Public Service Commission through a three-stage combined selection process called the Civil Services Examination. The first stage, the Civil Services Prelims is composed of two objective exams: one of General studies and one of a subject of one's choice amongst a given list of subjects.
For more on this visit : http://en.wikipedia.org/wiki/Indian_Revenue_Service_(IRS)