Is RRN not related to the generation of ID after complaint about no credit in accounts from the e-C

RRN is a number used in ecommerce refund. It is a unique number to trace the transaction on refunds on ecommerce transaction.

is it generated after one complain about non refund reflected in his savings bank account from a ecommerce site .

This is my query. Or is it related to a reference already available when ecommerce processed the refund at their end and submitted to the bank