How to buy stock after post market

1st i want to know shall we buy stock after post market closed or before pre market open.
What is the full form of BO CO & AMO

AMO does the same thing. It is After Market Order.
BO/CO are leveraged/margin products.
Please refer to for more information.

IOC (Immediate or cancel) for orders to be cancelled if not filled completely immediately.
More info: