http://droidangel.blogspot.com/2011/12/s5660dxkt4-asia-firmware-update-for.html

Asia version of Samsung Galaxy Gio GT-S5660 is getting the Android 2.3.6 Gingerbread firmware update with build number S5660DXKT4. This is an update from previous build Android 2.3.4 S5560DXKP6. The build date is December 2011 and more likely hitting on all South East Asian countries like Singapore, Indonesia, Thailand, Malaysia, Vietnam and Philippines.