how do i unlock my T-mobil i-phone 6

Unlock?

Passcode unlock?

If you forgot the passcode for your iPhone, iPad, or iPod touch, or your ...

Activation unlock? Only the owner of the Apple id to which it is activation locked can do that.

Carrier unlock? Only the carrier to which it is locked can do that. Contact them and see if they will do it.

Something else?

Please explain.

If you are asking how can you use your T-mobil iPhone with

a different wireless provider, you must contact T-mobil to see

if they offer unlocking and if you qualify. Only the wireless provider

to which an iPhone is locked can unlock it.

If this is not what you are asking, provide more details so someone

may offer a solution.