She made her international debut at the Junior meet in Germany in 2011 in which the Indian team was in sixth place. She was coached by Haryana-based Satguru Dass from the navy. She has taken part in prone, three-position and air rifle events but prefers three-position.
Koshy won five gold medals in Thiruvananthapuram at the State championship in the same year. She won silver in the Asian Shooting Championships and represented India in the 2013 and 2014 World Cups. Koshy took part in the 2014 Glasgow Commonwealth Games. Koshy won gold in the 2015 National Games women"s 50m Rifle Prone event, the first for Kerala.
