I need to find my Iphone6

Use any internet browser and log into www.icloud.com/find

Also see the following Apple articles for information about lost or stolen iPhones or iPads: If your iPhone, iPad, or iPod touch is lost or stolen - Apple Support and

Use the Find My app to locate a missing device or item - Apple Support

You can use any internet browser on any device and log into www.icloud.com/find

Also see the following from If Find My iPhone or Find My iPad isn't enabled on your missing device - Apple Support

If your missing device doesn't appear in the Find My app or at iCloud.com/find, you didn't turn on Find My. There's no other Apple service that can find, track, or flag your device for you. But there are steps that you can take to help protect your data.

Was "Find My" enabled on the iPhone that was lost BEFORE it was lost? If so, then as FoxFifth has mentioned, you can use Find My from a web browser. Alternately, you can use the Find My app on another Apple device that you are logged in with the same Apple ID as used with the lost phone to try to locate it.

However, the phone must be powered-on and connected to the Internet (either by cellular or Wi-Fi) for it to show up in Find My.