Well RBI might have some information here
https://www.rbi.org.in/commonman/English/scripts/PressReleases.aspx?Id=2398
But I can't access the .pdf to check for additional conditions due to DNS error on normal IP and even on VPN, so RBI is at fault.
Looking into India's biggest bank HDFC, here
https://www.hdfcbank.com/personal/useful-links/important-messages/pan-aadhaar-linking even HDFC says there "Please note; linking of Aadhaar with PAN does not apply to an individual who does not possess an Aadhaar number / Enrollment ID and is:- residing in the States of Assam, Jammu and Kashmir and Meghalaya."
BTW Income tax isn't "law of the land"?
IT and RBI works together usually as their core is "finance".
Though this
https://www.incometax.gov.in/iec/foportal/sites/default/files/2022-12/Refer Notification.pdf makes me confused as it says linkage is not mandatory unless one has aadhar, which my dad and brother do.
Btw, IDFC did tell me they can open my brother's/dad acc without linkage too IF I visit the branch with documents. They will manually process it but the branch was too far away. So certainly IDFC doesn't have this mandatory rule however for online or branch visiting our premises application, linkage has been made mandatory, that's where I have a problem.
and Linking of aadhar/pan isn't just for IT purpose, we are talking about opening bank account and SC has weighed in here aswell hence why "exempted" rule was made in the first place. Exemption was for opening bank accounts.