India’s Tata group of companies, which sells everything from salt to software, is known for being, well, old-fashioned. Genteel, even. It tries very hard to avoid any sort of controversy. That’s why the sudden removal of the group’s young chairman, Cyrus Mistry, and his replacement by his predecessor, Ratan Tata, is particularly startling. Apparently, not even Tata Sons Ltd, the oldest of Indian old-money concerns, is immune from a very Indian problem: mismanaging succession.