Visit the official UIDAI website
Open the Aadhaar Services section
Select Verify Email/Mobile Number
Enter your Aadhaar number and the mobile number you want to check
Enter the captcha code
Click Send OTP
If the number is linked, you will receive an OTP on that mobile number
If no OTP is received, the number is not linked to Aadhaar
You can also visit an Aadhaar Enrolment/Update Centre for confirmation
Carry your Aadhaar card and valid ID proof if required