@AnmolJiii dependent on what bank you use, instead of having regular FDs, you can setup linked FD or sweep FD (or other terminologies used by various banks). These FDs allow you to earn FD rates as well as be used for IPO applications. Only on successful allotment the FD of that much amount gets released, leaving rest as is. With this you get the benefit of both - FD rates on unutilized funds and IPO allotments that can give potentially much higher returns.
Hope it makes sense. I suggest you speaking to your bank’s relationship manager to understand better.