Why my iphone 6 doesn’t get the new update,? It shows that ios 12.5.5 is up to date !

Insert a SIM crad.

You can update your iPhone 6 to iOS 12.5.6, released August 31, 2022.

Check -> iPhone type & iOS version -> Go to Settings -> General -> About.

Then go to Settings -> General -> Software Update -> Download and Install.

You need about 5 GB device storage and good Service & Wi-Fi.

If they are On, turn Off Hotspot & VPN.

See the following Apple articles:

Update your iPhone, iPad, or iPod touch

Update your iPhone, iPad, or iPod touch - Apple Support (IN)

If your iPhone, iPad or iPod touch won’t update

If your iPhone, iPad, or iPod touch won't update - Apple Support

You can do the update via PC, see this Apple article: Update software on iPhone, iPad or iPod touch in iTunes on PC

Update software on iPhone, iPad or iPod touch in iTunes on PC – Apple Support (UK)

If you have a Mac see this Apple article: Update your iPhone, iPad, or iPod touch with the Finder

Update your iPhone, iPad, or iPod touch with the Finder - Apple Support