Backed by Soft bank, the Indian digital payment start-up Paytm, filed for an initial public offering (IPO) of up to Rs 16,600 crore ($2.23 billion), draft papers on Friday. The Noida-based company is backed by investors namely, Berkshire Hathaway Inc, China’s Ant Group, and Japan’s Soft Bank. The IPO proceeds will be used to strengthen the payment ecosystem and for new business initiatives and acquisitions.