IISERs are located at Behrampur, Bhopal, Kolkata, Pune, Thiruvanantapuram and Tirupathi. For admission to BS MS programme, Candidates have to appear for IISER Aptitude test. Candidates can appear for this exam under 3 Categories namely KVPY, JEE Advanced and SCB. You can check the eligibility criteria for each channel at: http://www.iiseradmission.in/index.php/pages/eligibility