Can an RF module be used for ZigBee?
Different kind of wireless modules, use specific modulation techniques. Some kind of modulations are FSK, PSK, GPSK, , QPSK, OQPSK and so many other techniques.

Different modulation means different technique to decoding received signal. It's so vital that receiver and transmitter use exactly same modulation and coding. 

For this reason you've to always use same type receiver and transmitter for communicating. you cant handle a Zigbee module by a RF module or a Bluetooth one. You also can't use two different type of RF module for communicating in most cases. Then for more reliable and secure connection Always use same type of modules for receiver and transmitter.