how to pull up voltage by 6v dc zigbee s2

XBee & XBee Gateway XBee - Zigbee
1

how to operate 6v relay by zigbee s2 ,pls give idea how pull up voltage in brief.

2

You have to place a level shift circuit it between. Check this link for refernce:
https://www.faludi.com/bwsn/xbee-level-shifting/