AMO(After Market Order) look likes its name means by this method you can place order while stock exchanges is closed. means if you can't purchase stocks in market time( 9:15 am to 3:30 pm ) then you can purchase share after that timing( 3:45 PM to 8:57 AM for NSE and 3:45 PM to 8:59 AM for BSE) except cover order and stop loss market order.