Rajamani was born on 1 January 1927, in Yangon, Burma. Her father owned a gold mine and was one of the richest Indians in Yangon. Her family was a staunch supporter of the Indian freedom movement and also contributed money to the movement. As a 16-year-old, inspired by Netaji Subhash Chandra Bose’s speech at Yangon, she donated all her jewelry to the INA. Realizing that the young girl might have donated the jewelry naively, Netaji visited her house to return it. However, Rajamani was adamant that he should use it for the army. Impressed by her determination, he renamed her Saraswathi. In 1942, Rajamani was recruited to the Rani of the Jhansi regiment of the INA and was part of the army's military intelligence wing. She is credited with being the First Indian Female Spy. During the Second World War, Rajamani was sent as a spy disguised as a worker into the British Military base in Kolkata to get the secrets of the British and share them with the INA. She played a key role in uncovering British plans to assassinate Bose during his secret visit to Indian borders in 1943. For almost two years, Rajamani and some of her female colleagues masqueraded as boys and gathered intelligence. While posing as a boy, her name was Mani. Once, one of her colleagues was caught by the British troops. To rescue her, Rajamani infiltrated the British camp dressed as a dancer. She drugged the British officers who were in charge and freed her colleague. While they were escaping, Rajamani was shot in the leg by a British guard but she still managed to avoid capture. Her work in the army ended when the INA was disbanded after World War II. After World War II, Rajamani's family gave away all their wealth, including the gold mine, and returned to India. In 2005, a newspaper reported that she was living in Chennai and was sustained by a freedom fighters’ pension. She donated her insignia to the INA gallery of the Netaji Subhash Birthplace National Museum in Cuttack, Odisha. She passed away on 13 January 2018 at age of 91.