While in college, Mitra pursued a career in modeling. Over the years, Koena has done commercials like ACP Whisky, Mirinda, Clinic All Clear, Maruti Alto. She is the winner of Gladrags Mega Model 2002. She later on went on to become the semi-finalist of Miss Intercontinental. She featured in quite a few music videos like Stereo Nation’s “Ishq”, “Aaj Ki Raat”, “Akh Teri”, “Channo” by Jassi.

Koena made her film debut in an item number in Ram Gopal Verma’s Road. This was followed by a small role in Musafir. Her lead role was in Ek Khiladi Ek Haseena directed by Suparn Verma opposite Fardeen Khan.