I want to upgrade my iOS to 15

Assuming you have a compatible device, see: Update your iPhone, iPad, or iPod touch - Apple Support

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

If the above Apple articles do not help, please post back with relevant information. 

Before You Upgrade:

1. Check Compatibility: Your iPhone 6s is compatible with iOS 15.
2. Backup Data: Backup your data using iCloud, or connect your iPhone 6s to your Mac and use Finder (macOS Catalina and later) or iTunes (macOS Mojave and earlier) for the backup.
3. Wi-Fi Connection: Ensure you're connected to a stable Wi-Fi network.
4. Battery Life: Make sure your iPhone 6s has at least 50% battery or is connected to a charger.

Troubleshooting Steps for iOS Upgrade:

Using iPhone 6s:

1. Restart iPhone: A simple restart often resolves issues.
2. Check Storage: Make sure you have enough free space to download the update. Go to Settings > General > [Device] Storage.
3. Software Update: Navigate to Settings > General > Software Update. If the update is available, tap "Download and Install".

Using a Mac:

1. Connect iPhone to Mac: Use a USB cable to connect your iPhone 6s to the Mac.
2. Open Finder or iTunes: Open Finder if you're on macOS Catalina or later, or iTunes if you're on macOS Mojave or earlier.
3. Locate your Device: Your iPhone 6s should appear in the sidebar. Click on it.
4. Check for Update: Click "Check for Update" and follow the prompts to download and install iOS 15.

Troubleshooting Steps for App Download:

Using iPhone 6s:

1. App Store Refresh: Close the App Store app and reopen it.
2. Sign In/Out: Navigate to Settings > [your name] > iTunes & App Store. Sign out and then back in.
3. Restart iPhone: A restart may resolve app download issues.
4. Check Restrictions: Go to Settings > Screen Time > Content & Privacy Restrictions to make sure installing apps is not restricted.

Using a Mac:

1. Open App Store on Mac: Log in to the App Store on your Mac and download the desired app.
2. iCloud Sync: If iCloud sync is enabled, the downloaded app should automatically appear on your iPhone 6s.

If you're still encountering problems, it might be helpful to reach out to Apple Support.

oluwatuyi241 wrote:

I want upgrade my iPhone 6s to 15:0

You can not update any device to 15.0.

You can update to the most recent, compatible version by following the steps provided by kb1951 above. If this is not working, YOU will need to provide details.

I want to upgrade my iPhone 6s to 15

Go to settings - general - software update and start there.

I want upgrade my iPhone 6s to 15:0

I go there now what did you want me to do now pls