If your mother is one of a nominee s mentioned mentioned by her parents, in the record of the Bank she will be entertained by the Bank, othewise it is a matter under official secret not to be discolsed to the persons other then account holders unless someone produces the certificate of legal heir
. Howver, your mother can orally appleal to the manager in confidence to have a look at the transaction in account , purely as a person favor, and sypathy to a senior person, in genuine need for such an information.
RTI will not help.