You can do this by trial and error.

fotodamaris wrote

We don't know your home, cement, wood, how many floors you have if any etc. etc.
Question does your ISP decides where to place main router or you do.

It's made of cement, there are two floors with 5 bed rooms (3 on the second floor and 2 on the first), not including dining and drawing room, tv lounge etc.

To answer your second question, I only have cable internet connection from my ISP, I've installed the router myself and it has to be in the room where the cable modem from them is placed, which is on the second floor. The cable modem cannot be moved as the cable wiring from the ISP only comes in one room so the router is also kinda stuck in that room. Though I've the liberty to put the router anywhere if I install a long CAT cable.

The configuration is like the following, wifi connectivity is excellent on the second floor but rooms on the first floor particularly suffer. Connectivity in room 4 is great however no signal comes in the Room 5 and drawing room (call it room 6) which is adjacent to it. I've to go to room 4 just to connect a device to the wifi, and come back to room 5 or the drawing where reception remains pretty poor. My main objective is to mainly improve wireless connectivity in these rooms without spending on range extenders.

[quote]one router will never do the job, on a 2 floor home, [/quote]
I confirm it. Solution with one AP isn't good in big home. My suggestion, you can search PLC transmitters with AP.

Center of home 4 feet off the ground.