In 1991, when India kicked off its economic liberalisation in the aftermath of a crisis, the government requested a committee headed by former governor of the Reserve Bank of India, M Narasimham, to submit a report on banking reforms. The committee’s report outlined the future trajectory of banking in India while making a strong case for limiting the number of large banks to four. Three decades later, the contours of that are emerging with the rise of a giant. HDFC Bank has merged with the country’s top mortgage lender, HDFC, which originally promoted the bank in 1994. There is of…