In order to file an income tax return (ITR), you must link your PAN & Aadhaar number to it as of April 1, 2019, unless you are specifically exempt. 

As a result, filing an ITR without connecting Aadhaar and PAN is not possible.

So, here's how you can link PAN & Aadhaar number.

Here's how you can check the link status of aadhar and PAN.