Could you enable the debug logs as per the getting started guide here? This will show what the API is actually responding with.

Will both machines be able to place orders simultaneously or will one get logged out?

You can refer to the documentation for api rate limits.

The rate limit is per API key. There is order related restriction per client id, go through the documentation here.

Go through the API rate limit here.

Reference : https://kite.trade/docs/connect/v3/exceptions/#api-rate-limit

Go through the rate limits here.

You can run multiple instances but within the API rate limits defined here.

kiteconnect.exceptions.NetworkException: Too many requests

Can I call my Zerodha api from two machines , simultaneously ( within the API usage limits) ?

while fetching order details - couldnt get the order id

Go through the rate limit here.

kite = KiteConnect(api_key="###my_api_key") #api key , access token and secret key is in string..!!

Does that mean I can create any number of KiteConnect instances without limitations?

Go through the rate limits here.

You can refer to documentation and FAQs here.

Go through the documentation here.

An access token is available from generate_session API not profile. Go through the examples here.

Can I use it this way to loop through implementing same strategy across all the accounts.

Should I include both of their orderid when placing sell order via api ?