Q: ilife is not free for iPhone 6s?

Those are the iWork apps (iLIfe as a concept was discontinued years ago), and as always, they require a purchase.

Did you buy this iPhone brand new or is it used?

Late 2012 Mac mini, macOS ?;  Watch, 38 mm silver AL, Watch OS 2.2.1; iPad Air 2 & iPhone 6+, iOS ?;  Apple Airport Express

From whom did you purchase the phone?

In Settings>iTunes and App Store is the ID used to originally setup the phone signed in?

Are the app in question listed in the Purchased section of the App Store?

Sign out of your Apple ID in the settings, restart the phone, sign into your ID again and then go to the App Store and try again.

This is how it is supposed to work: Get Pages, Numbers, Keynote, iMovie, GarageBand, and iTunes U for free on your iPhone, iPad, and iPod touch. Those apps ought to be preinstalled. I don't see the Apps Made by Apple link on my iPhone, but I can't be sure if that is because I already have them, or because the page has been redesigned without taking into account that it provided a unique pathway to this content.

tt2