Total income less than 12 lakhs but after processing it is asking to pay tax of 1 lakh

it is a typo error to be read as one lakh not 12 lakh

You need to reverify the details 

This could be happening for a couple of reasons.

First, check your AIS (Annual Information Statement) on the income tax portal under Services. If the portal detected income in AIS that is higher than what you declared, it will calculate tax on the AIS figure, not just your declared 9L. Common sources the system picks up: bank FD interest, dividend from multiple companies, unreported capital gains from stocks or mutual funds, or income from other sources you may have missed.

Second, if you have short-term capital gains from equity (say from stocks or equity mutual funds), those are taxed at 15% under Section 111A even in the new regime, and the Section 87A rebate of Rs 60,000 is NOT available to offset tax on that special-rate income. So a relatively small STCG can create a large unexpected tax demand even when your total income is well under 12L.

Step to diagnose: download your AIS from the portal and compare it against your declared income line by line. Where the figures differ, either include the correct income in your ITR or submit a feedback in AIS explaining the discrepancy. This [new regime tax saving guide for FY 2026-27](https://taxgarden.in/blog/tax-saving-under-new-tax-regime-fy-2026-27-strategies-india) also covers Section 87A conditions and what types of income fall outside the rebate.