I have lost my Enrolment ID slip/ Aadhaar letter, is there any way of finding the same?

Yes, In case your mobile number is registered in Aadhaar, you can find your Enrolment number (EID) or Aadhaar (UID) by clicking on “Retrieve Lost UID/EID” tab under Section Aadhaar enrolment on uidai.gov.in website or https://resident.uidai.gov.in/lost-uideid. Select EID/UID you want to retrieve and then enter your name and mobile number (as registered during Aadhaar enrolment). You will receive your EID/ Aadhaar number delivered on your email/ mobile number.

In case your mobile number is not registered in Aadhaar, you have to visit nearest Permanent Aadhaar Enrolment centre.