You can link your PAN to your Aadhaar by doing the following:

•  Go to https://incometaxindiaefiling.gov.in/ to access the income tax e-filing portal.
•  If you haven't already, register on it. Your user ID will be your PAN (Permanent Account Number).
•  Enter your User ID, password, and birthdate to log in.
•  A pop-up window asking you to link your PAN and Aadhaar will display. If not, click 'Link Aadhaar' under 'Profile Settings' in the menu bar.
•  Information such as a person's name, date of birth, and gender will already be included in the PAN information.
•  Compare the PAN details displayed on the computer to those listed on your Aadhaar. Please be aware that you  must obtain the same item if there is a mismatch.
•  Enter your Aadhaar number and press the "link now" button if the information matches.
•  You will receive a pop-up notification confirming the successful linking of your PAN and Aadhaar.
•  To link your PAN and Aadhaar, you can also go to https://www.utiitsl.com/ OR https://www.egov-nsdl.co.in/.