The limitation period of bank loans supported by the promissory notes only is 3 years.

Under the Limitation Act, 1963, the limitation period for simple contracts (including promissory notes) is indeed 3 years from the date when the debt becomes due. This means banks must initiate recovery proceedings within this period. After 3 years, the debt becomes 'time-barred,' though banks can still seek recovery if they can prove continuous acknowledgment or part payment.