After market orders are handled differently by various brokers. Some brokers like Reliance Securities and Zerodha allow their clients to place, modify and cancel AMO from 6:30 PM until 9:14 AM. Some brokers allow this only until 8:00 AM. You have to note that AM orders are collected without cross checking the available cash limit in your account. They are sent to the exchange after your cash limits have been updated and will get executed if you have the necessary funds for that position. Most brokers do not collect AM orders for some time in the middle of the night for a few hours because they would be running some processes on the servers.
The exchanges have a simple mechanism: All brokers have to send all their collected AM orders to the exchanges at 9:15 AM at market open in one go. How brokers collect the orders is entirely up to the broker.
For MCX the AM order timings will be different as the exchange opens at 10:00. AM orders for MCX are sent at 10, but collection of orders runs for 24 hours. Technically, you can place an AM order for MCX at 9:59 AM for today, and 10:01 AM for tomorrow.
The rules for AMO (after market orders) are different based on which broker you trade with. There are even some brokers who don't allow you to place AMO.
If you are trading at Zerodha, there was this restriction earlier, but not anymore. Now you can cancel/modify your AMO until 9.15 AM. We have a blog post on the same, click here to check it out.
Not true… We can modify AMO orders until 9:15…
Hope you arent thinking of pre market orders when you say AMO, Pre market orders cant be placed post 9:07
Thanks for the clarification