What I want to do is have a complete control on beacon remotely through web/mobile app (RestApi). I already gone through following sites,
1)https://nectarkast.com/index.html 2)https://kontakt.io/products-and-solutions/beacon-software/
How do these site working? Are they using some custom beacons that has Wifi or network connecting functionality, any help would be really appreciable.
You need (a) a beacon with internet access or (b) a base station near those beacons with internet access and the ability to connect to them via Bluetooth to configure them.
It is also possible to build beacons using Lora, SigFox, or other IoT radio technologies that effectively gives a very low power internet connection that uses little battery.