My ios 16 not downloading just showing 6 or 7 hours remaining i have good wifi connection while my friend got it 10 minutes

Check your WiFi Router / Modem for --> Recommended settings for Wi-Fi routers and access points ...

Connecting to Wifi is the first part and then getting connected to the Internet is the second

1. If you connect to Wifi, doesn't necessarily mean you are connected to the internet. If you are not connected to wifi could be a problem with iPhone settings or Router/Modem Settings
2. If you are not connected to the internet is the sole issue of Router / Modem Settings. Contact your ISP immediately

Optimize the range of the mobile network, see this Apple article:

If you see No Service or Searching on your iPhone or iPad

If you see No Service, Searching, or SOS on your iPhone or iPad - Apple Support

Charge the battery > 70%

Hi,

If someone else was able to download the update on the same wi-fi network connection with no issue, try to delete the update in your Settings and download it again.

Settings > General > iPhone Storage > iOS 16 Update > Delete Update

After its deleted, go to Settings > General > Software Update > Download and Install.

Make sure you are remaining on Wifi, and your phone is plugged into the charger.