Top software services exporter Tata Consultancy Services (TCS) has approved the buyback of shares worth Rs 18,000 crore and fixed February 23 as the record date for determining the entitlement of equity shareholders. "This is further to our letter dated January 12, 2022, informing the decision of the board of directors of the company to buyback up to 4,00,00,000 fully paid-up equity shares of face value of Re l each at Rs 4,500 per equity share for an aggregate amount not exceeding Rs 18,000 crore," TCS had stated in a regulatory filing on Saturday.