The Blue Aadhaar Card, also known as the Baal Aadhaar Card, is a specialised form of the Aadhaar card designed for children under the age of 5. It serves the same purpose as a regular Aadhaar card by associating the child's biometric and demographic details with a unique 12-digit identification number., FAQs News, Times Now
If you have not linked your PAN with Aadhaar earlier and want to do it now, it can very well be done online or offline. However it will involve payment of a late fee of Rs 1000. But if due to any reason like date of birth mismatch, etc the linkage could not be done, then you will have to get it corrected first.