"ABN Amro received signs mid-2014 of some employees possibly not complying with internal guidelines," Bloomberg news agency quoted bank spokeswoman Brigitte Seegers as saying.
Dutch media reported that the bankers had helped Indian clients set up private accounts instead of business accounts.
Private accounts are subject to less strict rules aimed at preventing money laundering and terrorism financing.
An internal enquiry led to the six bankers leaving ABN Amro and the Indian accounts being closed.
ABN Amro was nationalised in 2008 in the middle of the financial crisis.