I searched everywhere, but i am not getting any darn answers. I have a modem+router, but its range is really poor. So, i am thinking of getting a router only this time and put it on first floor and have it connect to my modem so that it can work as wifi-extender/repeater and so that it can cover the whole house. -All I want to know is that can i do that? if yes then how? Please help me as it is really urgent and i am from India, so suggest me something from Amazon.in only.
You can do it but your router must have settings that allow it be either a repeater or an access point. As a repeater wireless it's not as good performance as an access point which requires a wire from the modem between the lan ports. https://www.digitaltrends.com/computing/how-to-turn-a-router-into-a-wireless-repeater/ That seems to think that you would have to flash dd-wrt firmware on the repeater but I think newer routers would allow it but you'll have to research which ones will. I've only done the access point with a wire.
Using a repeater is at the end of the day not a very good solution. If you're unable to use wires to get across the house I suggest powerlines. A good place to start: http://www.devolo.com/ I use DD-WRT myself but I'm simply not a fan of repeaters. Access Points is a different story.
Thanx for the reply guys. I am getting netgear wifi extender and lets see how well it performs. I don't have that much speed to begin with, all i need is good coverage, enough to cover the whole house.