Bihu is folk festival of:

The correct answer is Assam . Key Points Bihu is a group of three important Assamese festivals in the Indian state of Assam – 'Rongali' or 'Bohag Bihu' is celebrated in April, 'Kongali' or 'Kati Bihu' is celebrated in October, and 'Bhogali' or 'Magh Bihu' is celebrated. Assam - Ambubachi, Bhogali Bihu, Baishagu, Dehing Patkai. Additional Information ​List of Indian Festivals State List of Indian Festivals Assam Ambubachi, Bhogali Bihu, Baishagu, Dehing Patkai Jammu and Kashmir Har Navami, Chhari, Bahu Mela, Dosmoche, Jharkhand Karam Utsav, Holi, Rohini, Tusu Karnataka Mysore Dasara, Ugadi Kerala Onam, Vishu