Courtesy Gumnami Baba a Case History by Adheer Som. Subhas Bose received initiation in Kriya Yoga from Babu Barada Charan Majumdar in June 1939. Barada charan was known to Kavi Kazi Nazrul Islam and Dilip Kumar Roy, both friends of Bose. Kriya Yoga is the tradition carried forward by Lahiri Mahasaya - Shyamacharan Lahiri, the guru's guru of Parmahamsa Yogananda who belonged to the same tradition. Bose was already interested in Tantra and he had also been greatly influenced by Swami Vivekananda, the universal teacher of Vedanta. However no other reference to the spiritual initiation is found in any other biography or for that matter in Bose's own writings. So Bose must have been extremely secretive about his spiritual progress or his personal life.
Picture courtesy Overman Foundation