How can I extend the range of Apple airplay to reach in different location in a building ?

airplay is not a communication directly between the appleTV and the ios or mac device they both communicate using the wifi router on your network so as long as the are on the same subnet and the router allow the ports require you can be far away from the appletv

The range is as far as your Wi-Fi network.

It would be an issue with your network, not airplay.