Q: Hi my name is Andrea I was given as a gift the iPhone6 I would like to know how I can unlock it?

What you need to know is

- Country of purchase iPhone (in this case is USA)

- Carrier that iPhone is Locked to (USA carrier:  AT&T, T-Mobile, Verizon, Sprint...)

- Blacklist status of that iPhone (Under contract, Lost, Stolen)

If you know all information only can unlock that iPhone but some case can't unlock ie. iPhone in contact or blacklist

Only the previous owner can unlock the phone. Either that or you need to receive the previous edit OS er's Apple ID and Password.

These are the official instructions for preparing a phone to be given away.

What to do before selling or giving away your iPhone, iPad, or iPod touch - Apple Support

The question is whether the phone is currently locked to a particular carrier. If it is, you'll need to call that carrier to unlock the phone. You can tell them you're not in the US (and don't plan to be)... that is usually sufficient.