how to emonpi communicate with the emonweb using rf module? and is it possible to without rf module?
You are using terms there that I do not recognise - “emonweb” is not a word we use.
The emonTx, emonTH & emonGLCD use JeeLib and the Hope RFM69CW to communicate with another Hope RFM69CW which is mounted on the ‘emon’ circuit board carrying the analogue inputs and the Atmega328P in the emonPi. That circuit board is available separately, but it comes with the RFM69CW.