Collecting loan documents from bank by a third party

The procedure is

- Official mail (bank communication) from first party to bank to issue documents to concerned

- Letter with signature from first party to bank to issue documents to concerned

- or duel RTI from first party and concerned party to issue documents

In response to your query

To get the documents from the bank through a third party you will have to write a formal letter with proper attestation to the concerned officer about the same and send the relative documents to the bank so that they can identify the third party and establish the relationship between himself and you and most importantly you will have to also give an NOC to suggest that the bank will not be liable for any further actions once the documents are handed over to the said person. 

Apart from this there are different policies for different banks so you better connect with the support staff of the bank you had taken loan from to explain anymore details to you.

Regards,

Aryan Raj