activation lock for iPhone 6

It appears that your iPhone is Activation Locked to an Apple ID which is not yours. Did you just buy that iPhone? You will need to locate the seller and will need his/her assistance to enter that Apple ID and Password to remove the Activation Lock. You are not going to be able to do anything with that iPhone unless you have the Activation Lock removed by the original owner.

Axel F.

Only the owner of the account used to lock it can remove the activation lock.

Talk to whoever you got it from.