how to restore iphone 6 s

By "restore", did you mean to reset/erase the phone back to factory default settings?

Or, by "restore", or did you mean that are you trying to use a backup of the phone to restore or reload the data in the backup back to the phone?

In either case, you should plan to use either a Mac or PC. Do you have one available?

Which question does your "yes" apply to?

This one? By "restore", did you mean to reset/erase the phone back to factory default settings?

Or this one? Or, did you mean that are you trying to use a backup of the phone to restore or reload the data in the backup back to the phone?

Do not answer "yes" to both questions.