Make sure, you have added the correct postback URL in the developers console. Go through postback FAQs here.

b"

Go through postback FAQs here.

Cannot modify Order is being processed ...."

httpRequest.ContentType = "application/x-www-form-urlencoded";

Go through Postback FAQs here.

BO is not supported

To check the status of an order, can we do:

Go through postback FAQs here.

{"exchange": "NFO",

You can use order margin API to know the MIS margin requirement for required contract.

I have a command that calculates margin every 10 seconds

You won't receive postback update for every order status. Go through postback FAQs here.

Go through python order FAQs here.

You can go through order placement FAQs.

Can I get margin data without placing an order?

You can use order margin API to know about co margin requirement.

You can go through the API response structure here. A successful response structure will return the status key with the value success.

You can go through order rate limit FAQs here. what is account-level risk check Kite has?

{'transaction_type': kite.TRANSACTION_TYPE_SELL,'quantity':stock.get('quantity'),'order_type' : kite.ORDER_TYPE_LIMIT,