How can I unlock my iPhone 6?

Which One?

If you forgot the passcode on your iPhone, or your iPhone is disabled or unavailable -

If you forgot your iPhone passcode or your iPhone is disabled - Apple Support

If your phone is carrier locked - How to unlock your iPhone for use with a different carrier - Apple Support

How to unlock your iPhone for use with a different carrier - Apple Support

If your phone is Activation Locked - How to remove Activation Lock -

How to remove Activation Lock - Apple Support

There are different kinds of locks. We can't see your phone, so we must ask you......What is the message on the iPhone's screen?

Activation Lock?

Unavailable?

Security Lock?

Something else?