The minimum threshold limit depends on your age. If you are under 60 years, the threshold limit would be INR 2.5 lakhs. For senior citizens aged between 60 and 79 years, the threshold limit is INR 3 lakhs. For super senior citizens aged 80 years and above, the minimum threshold limit is INR 5 lakhs. If your gross income is within this threshold limit, you would not be required to file an income tax return.