internet -> modem -> arduino server -> arduino client -> modem or directly -> pc and cellphone
if it's possible to multi-client I thank you
No.
NRF24 cannot talk to phone or PC, or the modem, for that matter. They can only talk between themselves.
The whole concept is pointless anyway, as the modem can talk directly to both PC and phone. That is what modems do, and anything in between is redundant. If you have already bought the NRF24s, think about this for a few more minutes, you will probably come up with something more sensible, and relevant to Arduino.
I just want to send the internet via ESP8266 to the NRF24L01+ and receive with another, to route I would use the ESP8266
Since ESP can talk to WiFi devices and, perhaps depending on the type, to NRFs, such a chain of communications could be made to work, but it is really not the sort of thing you would want to show your mother.
Really?
NRF24 use SPI bus. If ESP8266 has SPI bus, they can connect. It is possible, but it is stupid.