Informing the BSE in a filing, TCS board of directors has reportedly approved a proposal to buyback up to 5,61,40,351 equity shares for an aggregate amount up to Rs 16,000 crore. The buyback size works out to 2.85 percent of firm's paid up equity capital, at Rs 2,850 a share. The buyback is subject to approval of the members through a special resolution through a postal ballot, the company said.