is there any xbee c library which is compactable to atmega2560.library which is to read/write configuration of xbee through atmega2560.
I believe you are looking for a generic XBee API library to interface with a non-programmable XBee. Am I right?
Are you using an Arduino for that?
This sub-forum is about the Programmable variant of the radio but if you are interested using arduino to communicate with an XBee running in API mode then perhaps you are looking for the following: https://github.com/andrewrapp/xbee-arduino