If you have the Samsung Galaxy S6 just unpacked and tested the first features, then you may have noticed that under "Settings --> Smart Lock -->Lock screen and security à Secure lock settings" the feature “On body detection” is not available. With the on body detection your device remains unlocked automatically while you carry it with you. We already know this useful function from the Samsung Galaxy S4 and S5.
The detection is not available at the first glance at the new Samsung Galaxy S6 and the reason is the following.
The Google Play services have not yet been updated in the short time after switching the device on. Only with the current update of Google Play services the support of “On-Body detection” is installed on your Samsung Galaxy S6. After at least 24 hours this function should be available and usable on your Samsung Galaxy S6, because after this period, the Google Play Services update has been downloaded and installed on your device.
You now know why you don´t find the on body recognition on your Samsung Galaxy S6 within the Smart Lock submenu.