When it comes to a comparison, the decision entirely depends on various factors such as your risk appetite, the period of investment, etc. When it comes to ELSS the lock-in duration happens to be 3 years and the risk factor is a tad bit higher. However, for FDs, the lock-in period can range between a few days to 10 years and there is very little risk involved. While ELSS have a higher potential for better returns, FDs are secure and the returns are guaranteed.