Help Updating Issue for S6

[Swagbro]

Hi,

I have a Samsung galaxy s6 and it's currently running lollipop 5.1.1 but i want to update it. Whenever i go to update it, it says check back later, latest update already installed. However, i know for a fact that other s6s have been updated further than lollipop. I need some help to update it further than lollipop. I have tried everything i can think of. The last thing i wanted to add is that i have no carrier, i am using my phone without a sim card, not sure if that information was necessary, but the more information the better!

Thanks

 

[svim]

Have you tried using Samsung's Smart Switch or Samsung's Kies to upgrade your firmware?
Smart Switch
https://gs6.gadgethacks.com/how-to/use-smart-switch-update-your-galaxy-s6-even-its-rooted-0162897/
Kies
https://www.recovery-android.com/firmware-upgrade-with-samsung-kies.html

If neither of those utilities can guide you through the upgrade process, take a look at doing so manually using Odin. You'll have to use install the Odin utility on a Win PC, and download the appropriate stock ROM (be absolutely sure to use a ROM specifically for your model of S6, do not substitute for a 'close-enough' ROM).
Odin
http://www.droidviews.com/download-odin-tool-for-samsung-galaxy-devices-all-versions/
Reliable sources for Samsung stock ROMs:
sammobile
https://www.sammobile.com/firmwares/
updato
http://updato.com/