Ruchi is a co-worker of Bernadette. Her first appearance is in the Season 11 episode "The Relaxation Integration". Both Raj and Stuart compete for her affection. She doesn't want a relationship, but did agreed to be friends with them.
It appears that in "The Geology Methodology" she starts a casual relationship with Raj. In "The Tesla Recoil" Ruchi admits that she was trying to steal Bernadette's projects while she is on bed rest. After Raj talks to her about the office politics, Ruchi dumps Raj.
She is portrayed by Swati Kapila.