How much solar radiations is essential for generation of electricity for whole house?

There isn't a simple answer for this.
It depends on how energy efficient the house is.
It also depends on how energy efficient the OCCUPANTS are.
Also, in many cases (especially urban), you're going to have space constraints on how much capacity you can implement.

Also, are you simply looking to implement solar and using the grid as a "battery"?
Or are you looking to do on-site power storage (think "Tesla PowerWall") to minimize grid usage?

Or are you looking for a minimal "completely off-grid" setup?

There is a good web site for this. It is called PVWatts....Search in Google... Considered by most the gold standard and calculating array size.

You will need your current/yearly electrical usage from your power bill.

You will still have to figure out the net metering options for your location.

If you list your location there might be someone close that knows what the local power company requires.

SolarPanelTalk. com is a sister site to this one that has many good people on it. Some can be rough around the edges but ignore them.

Good Luck

Average household use Between 5000 kilowatts to 10000 kilowatts hours per years. and also depends on your annual energy load. Nishan Singh