Does F5 Big IP supports XML API for interacting with the device

There are a lot changes between version 9.x 10. an 11.x

You should write an icontrol script that check f5 version and then use the appropriate command.

For every icontrol interface you can find for which version is available. Look this for an example: https://devcentral.f5.com/wiki/iControl.LocalLB__NATV2.ashx