Tata Sons approached the Supreme Court today challenging the restoration of Cyrus Mistry as the executive chairman of the group by company law tribunal NCLAT last month. Cyrus Mistry was restored as the executive chairman of Tata Sons, one of the country's oldest and largest conglomerates, on December 18 by the National Company Law Appellate Tribunal (NCLAT), three years after his dramatic sacking at a board meeting following which Ratan Tata took over as interim chairman.