It sounds like you are unable to locate your iPhone at http://www.icloud.com, it tells you that your devices are offline even though it is turned on. I suggest the troubleshooting found in the following article named:
iCloud: Troubleshooting Find My iPhone, iPad, iPod touch, or Mac
"No location available," "Offline," or "Location Services Off" alerts
This can occur if:
- The date on your device is incorrect. Choose Settings > General > Date & Time to check and set the date.
- Your iOS device is currently off or not connected to a data network (Edge, 3 or 4G, or Wi-Fi). Wait a few minutes and try again.
- Your iPad (Wi-Fi only), iPod Touch, or Mac is currently off or not connected to a Wi-Fi network.
- Location Services is not enabled on your iPhone, iPad, or iPod Touch (Settings > Privacy) or on your Mac (Date & Time) preferences. Learn more about Location Services on your Mac:
- You are located in a country where Apple does not offer this feature. This feature may not be available in all countries due to technical limitations or local law.
Location appears to be old or inaccurate
This can occur if you previously located your iPhone, iPad, iPod touch, or Mac and your device has not yet provided an updated location to iCloud.
Note: Your device's last known location will be available for one day. After 24 hours, you will no longer be able to see this last known location if the device is offline or otherwise unable to connect to Find My iPhone to provide an updated location.
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All the best,