The government of India recently changed the name of Rajiv Gandhi Khel Ratna Award to Dhyan Chand Khel Ratna Award, Dhyan Chand served in the Indian army as a:

The correct option is Major.

Explanation:
Major Dhyan Chand was an extraordinary Indian field hockey player, widely considered one of the greatest players in the history of the sport. He joined the Indian Army in 1922 as a Sepoy (soldier) in the 14th Punjab Regiment and was subsequently promoted through the ranks over his distinguished service.

He retired from the Indian Army in 1956 at the rank of Major.

In August 2021, the Government of India officially renamed India's highest sporting honour, the Rajiv Gandhi Khel Ratna Award, to the Major Dhyan Chand Khel Ratna Award in recognition of his iconic legacy and unparalleled achievements in hockey.