The long-sleeved blue shirt and the Tube Investments of India logo on the pocket sit well with Vellayan Subbiah. His room is spartan and the Mac on the table gets a break, during BT’s meeting with him. His mobile is charging in another corner. A replica of the FIFA World Cup trophy finds a pride of place.It’s Chennai, and the summer is just about making its presence felt. No footwear is allowed in the room, and we are seated cross-legged on the floor. Subbiah, a fourth-generation member of the storied southern conglomerate that was founded in 1900, oversees three of...