Dear Lakshmanan, ICAR is a National Level Entrance Examination for candidates interested in pursuing Agricultural courses across India. 64  ICAR Institutes participate in this admission process. In Tamilnadu, there is Central Institute Brackish Water Aquaculture - ICAR in Chennai, Agricultural College and Research Instiyute, Coimbatore, and various branches at different locations.So if you qualify in ICAR based on the merit, you can join in Tamilnadu colleges.