[Android Central Question]

I have a Samsung Galaxy S6 however, I am unable to select the Software Updates option in About Phone. When I click on it nothing happens. It doesn't give me the check for updates option or anything. It just remains on the main screen.

[belodion]

Is it a carrier-locked phone?

[VidJunky]

Where did you get the phone?
If you ordered online you may have received a formally rooted device, in which case it may not have update options. The easiest way to check the device to see if it was or is rooted is to boot the phone into Bootloader. At the top of the screen it will give the phones status,
Locked (no other message) = never rooted or unlocked
Unlocked (no other message) = the phone has been unlocked but nothing has been changed
Locked or Unlocked with Tampered = means that at some point the device has been modified, locked means that it was relocked and unlocked means that it is still open for modifications

I am not 100% on rooting anymore, as it has been years since I was interested in such things, but it used to be that a device that was unlocked could not receive OTAs which would explain why you are unable to search from the device. It also used to be that if you locked the device with a stock version of the OS installed you could then get OTAs, I believe even if it had one time been modified (Tampered).

Not to sound all conspiracy theorist on you but once unlocked and rooted devices can be set up to return any entered information to an IP without showing any outwardly signs of this happening. I've seen more than a couple of cases of SOs checking up on their boyfriend/girlfriend this way. Remote access is also possible thru root, which means that photos and videos can be taken, again with no outwardly signs of this happening. Often but not every time, as humans will be human, sellers will disclose if a device has been previously rooted or unlocked during the sell if they are honest. A quick search can describe to you how to boot your phone into the Bootloader to see your phone's state.