My unit is running on android 5.1 version, with AT&T sim.
It run on OS 5.1 with AT&T.
My question is, can you upgrade to the latest android versions?
Can you unlock,so I could use my t_mobile sim?
1) You cannot update to an official Android 7 or 8 release. Samsung simply didn't make one.
If you go to this forum, there are instructions where you can updated to a 3rd party version (which looks like the Nexus Androids).
2) I doubt that AT&T locked tablets. Take it to a T-Mobile retail store and have them try a SIM on it.
If it is locked, AT&T unlocks via this form:
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