Possessing both speed and guile, Ranjana Chanu is known for her exploits down the flanks, both as a winger and as a fullback. She has been a part of the national setup since a young age, representing India in the 2015 AFC U-19 Women's Championship qualifiers at just 15 years of age.

Ranjana debuted for the Indian senior team in 2018. She scored a brace, her first goals for the national team, the following year in a 10-0 win over Turkmenistan in the Turkish Women's Cup. In November 2019, she scored a crucial equaliser in a 1-1 draw against higher-ranked Vietnam in a friendly in Hanoi.

Additionally, Ranjana was the first-choice left-back for Gokulam Kerala FC in their historic AFC Women's Club Championship debut in November 2021.