Hi,

Having knowledge about finance is really important for a bank PO so it is necessary to keep yourself updated on the courses.

Here are some of the online portals where you can easily get free or paid courses in accounting:

1. MOOC
2. Alison
3. Udemy
4. edX
5. YouTube
6. Coursera
7. Online Universities

The topics include accrual basis of accounting, payables or receivables, intermediate accounting, advance accounting, control and cash monitoring, investment accounting, accounting for entrepreneurs, bookkeeping etc.

Hope it helps!