Lupin Ltd. (LPC), the world’s largest maker of drugs to fight tuberculosis, is considering selling its unit that markets medicines in India, said two people with knowledge of the matter. Founding shareholders who own a combined 47 percent of the Mumbai-based company have started the process of finding a buyer for the operations, said the people, who declined to be identified because the discussions are private. The Indian business may be worth at least $1 billion, one person said. ling the Indian medicines unit, which accounted for 32 percent of Lupin’s 57.1 billion rupees ($1.3 billion) of revenue in the year ended March 31, may help finance investments in more profitable markets overseas.