China’s fastest-growing luxury auto seller is not from Europe, Japan or the United States. The honor goes to Tata Motors from India. Meanwhile, Shanghai Electric earns its largest revenue outside China from India. Anil K. Gupta, the Michael Dingman Chair in Global Strategy and Entrepreneurship, shows how Indian and Chinese companies are winning in each other’s markets in his new book, “The Silk Road Rediscovered.” “They are whetting their appetite for further global expansion, ensuring that they will have two of the world’s four largest economies by 2025,” Gupta says.