Flipkart co-founder Sachin Bansal-backed Navi Mutual Fund (Navi MF) has announced the launch of Navi Nifty Bank Index Fund, an open-ended passive equity scheme that will replicate the Nifty Bank Index. This new fund offer (NFO), which opened on January 17, will be available for subscription till January 31. However, investors can buy the mutual fund scheme even after the NFO period is over.