Sensei Ajoy Halder,starting his Kyokushin training at the age of 4 years.sensei Ajoy Halder was enged Kyokushin kai-kan karate under the control of late sensei Ratan Chakraborty in the Boys Training Association at kalighat Kolkata (India). In the year 1997 he was appears in the gradation under the control of sensei Nirmallya Sikdar and he achieved 98% marks in the exams and got double promotion,He also appears in the year 1999 Oyama Cup in Maddhya Pradesh (M.P) and category kumite and was champion. Next achievement kata category in the year of 2001 and was champion and also Garia, Kolkata Kyokushin National Tournament. He was also join in Kyokushin kan International in Japan in the year 2014. presently he create his own organisation the name of kolkata Kyokushin institute. In the year 2015 He joined Ishinkan Kyokushin karate organisation (Austria) as a Branch Chief Of India,after that in 2018 month of September he was appointed as Indian branch chief of international federation of Kyokushin Kai kan karate.