circuit diagram for radio frequency based remote control system for ac main using fm technique?

Answer 1

Go to this page, they also have the circuit diagram:
http://www.electronic-circuits-diagrams.com/remotecontrolsimages/remotecontrolsckt5.shtml
Whether it is working on AC mains is only determined by whether you use a power supply instead of a battery.
So you add a 9 Volt power supply to above, and it is "mains powered": http://www.electronic-circuits-diagrams.com/psimages/powersuppliesckt2.shtml