The dabbawallas of Mumbai deliver box lunches — called tiffins — to whitecollar workers all over the vast city. They are legendary for their near-perfect service: for every six million lunches sent, only one will fail to reach its intended destination. The Tiffin is about that one time in millions when a box goes astray, changing lives forever.

When a note placed in a tiffin is lost, a newborn — Kunal — is separated from his mother. Twelve years later, Kunal lives as a virtual slave under the thumb of his foster father, Seth. With danger and oppression making it impossible to stay where he is, Kunal asks his friend Vinayak, an aging dabbawalla, to help him find his birth mother. Vinayak introduces Kunal to the tiffin carriers, and a plan is hatched. Along the way, Kunal learns what it means to be part of a family.