It depends on the following factor;
1. Your computer resources
If your computer has very less resources, say you have a little RAM, then your program may take more time to process the code/instructions, thus eventually resulting in more time to place a order.
2. Your network speed
If your network is fast, then it will take less time for order request to reach the API server.
3. Where you are located
The more you closer to Broker Server (OMS), lesser will be the order place time.
4. Network traffic at API server
If there is too much traffic at API server (like during high volatility), then it may take more time to place a order or your request may be timed-out.
Typical Time to Place a Order
Mumbai (Cloud Server) – ~36ms
Bangalore (Cloud Server) – ~68ms
Singapore (Cloud Server) – ~132ms
Chennai (Local Network) – ~272ms