How orders gets routed from Zerodha's terminal

How orders gets routed from Zerodha’s terminal to NSE/BSE exchanges?

They use leased lines which connect to the exchanges.

You mean from Pi / Kite it goes directly to exchanges. Do exchanges also use same software of Pi or Nest?

Yes. Why would the exchanges need to use Pi or Nest. These are customer facing platforms. Check this video

Okay. I understood.