National Company Law Appellate Tribunal (NCLAT) today reinstated Cyrus Mistry as the Executive Chairman of Tata Group while ruling the appointment of N Chandrasekaran as executive chairman illegal. The restoration will come into effect only after four weeks. Cyrus Mistry and family holds a minority stake in the Tata Sons group with 18.4 percent of shares. With this development, Tata shares fell by 5.25%.