Hello Vishal,
Please tell how you want your project to work. There is a similar project on EG for prepaid energy meter – engineersgarage.com/contribution/using-arduino-build-prepaid-energy-meters. If you intend to make something different from this, please clear how your project should work and where you are facing problem. In the EG's Project, user can buy a prepaid recharge of electricity, a smart device attached to regular energy meter monitors power consumption and when the recharged power is about to consume, SMS alert is sent to the user to make a recharge again.