Follow this guide if you purchased a set with Range Extenders.
Range Extenders work best when they’re placed between the far ends of your home and no more than two rooms away from the Router. Also try putting them in an open space.
As a general rule, Wifi Extenders work best when they’re no more than 2 rooms away from each other. For example, if the far end of your house has weak WiFi, don’t put a Wifi Extender in that exact spot. Instead, put it partway in that direction. Try to place the Extenders in an elevated position like on a shelf.