RSB Retail India, formerly RS Brothers Retail India, a multi-brand retail chain with a strong presence in South India, is set to file its draft red herring prospectus (DRHP) with market regulator Sebi soon to raise around ₹1,500 crore through an initial public offering (IPO), said people familiar with the matter. The issue is expected to be acombination of a fresh share sale and an offer for sale (OFS) by promoters and existing investors, according to sources. Motilal Oswal Investment Advisors and HDFC Bank are the book-running lead managers (BRLMs) to the IPO.