Tata Consultancy Services has a rigorous recruitment and selection process across four levels - work force, frontline, middle management, and top management. For the workforce level, candidates apply online or via ads and undergo written and technical interviews. For frontline level, internal candidates are evaluated on performance while external candidates face additional assessments like group discussions. The middle management level involves fast-track programs and technical interviews for internal promotions or external hires. The top management level does not recruit externally and involves interviews and presentations for selection.