[4] As an acting subedar (paid), he fought in the Burma Campaign, during which he won the Indian Distinguished Service Medal (IDSM).

[Gurkha Officer] was 2nd in command of a company which was ordered to counter-attack at night against strong Japanese forces, estimated to be the major part of a battalion and supported by mortars and infantry guns.

During the course of the fighting, which lasted the whole of the next day, and during which quite early in the proceedings his company commander was wounded five times, this Officer displayed the greatest coolness, courage and military skill.

[8] In the full citation, which was not published, Rai was commended for:[8] ...his dash and courage, combined with high qualities of leadership and initiative shown by this Gurkha Officer on all occasions when his company has been in action.

[10] On 20 November 1956, he was seconded for service with the 8th Battalion of the Assam Rifles,[11][12] and was then assigned to the Village Guards (Naga Hills, Tuensang Area) on 1 December 1957.

9-Pres/62.—The President is pleased to approve the award of the ASHOKA CHAKRA, CLASS I, to the undermentioned personnel for most conspicuous bravery: Captain MAN BAHADUR RAI (IC-5261).

(Effective date of award — 3rd May 1961) In April–May 1961, Captain Man Bahadur Rai (IC-5261) took part in a series of actions against a body of hostile Nagas who had entrenched themselves in a very difficult, densely wooded, hilly region interspersed with numerous ravines.

Captain Rai, knowing that heavy casualties would result if he were to attack frontally, took half a platoon, crawled through the thick undergrowth and scaled up the steep side while exposed to a hail of close range fire which covered his advance.

Throughout this period, he repeatedly showed conspicuous bravery, unselfishness and indomitable courage in very difficult and dangerous situations.