There are six ways to verify an ITR. Five can be done electronically and one is done offline.

Net banking: On the e-filing portal, visit e-verify page. Under the net banking option, select the bank your net banking is active with. You’ll be redirected to the net banking page of the bank. After logging in, select the e-verify option to complete the process.

Aadhaar-based OTP: You can opt for this method under two conditions. The first is that your PAN should be linked to your Aadhaar and the second is that the Aadhaar number must be linked to an active mobile number. If you meet the two prerequisites, you can select the ‘verify using OTP on mobile’ option available on the e-verify page.

Bank account: Electronic Verification Code (EVC) can be generated through the bank account which is pre-validated on the e-filing portal. A bank account needs to be pre-validated if you are expecting to get an IT refund. When you select the bank account option to e-verify, EVC is sent on your mobile number registered with the pre-validated bank account.

Demat account: This option is available only to those taxpayers who have a demat account that is pre-validated and EVC-enabled on the e-filing portal. These are done before filing ITR returns. When you select this option, EVC is sent on the mobile number and email ID linked to your demat account.

Bank ATM: Only seven banks allow e-verification using ATM card—Kotak Mahindra Bank, Central Bank of India, Canara Bank, ICICI Bank, State Bank of India, IDBI Bank and Axis Bank. If you have an account with any of these banks with your PAN linked to it, visit an ATM and generate EVC using the ATM card. Once you have the number, go to the e-verify page and select ‘I already have an EVC’ option to complete verification.

Source: https://www.livemint.com/money/personal-finance/filed-your-income-tax-return-here-s-how-to-verify-it-11637513738242.html