Her main responsibilities will be to bring stability to the agency, which has been without a chief executive since March this year, and drive new business.
Kar began her career in 1992 with Grey (then Trikaya Grey), before moving to the creative agency Mudra. She then joined Grey for a second spell before moving to Vibrant Media, her first foray into media planning and buying.
She said: "I was toying with the idea of joining the agency for a while, but finally took it up because it opens up a number of opportunities. The challenges are wider and there's new scope for learning."