How should i know my iphone 6 plus is original or fake

If iTunes recognizes it, then it's not "fake".

Where did you buy it that this is a concern?

That doesn't change the answer.

You have a gray market phone. You bought it from an unauthorized source. There is no way for us to know the history of that phone.

Apple does not do business in Pakistan and there is no support for the iPhone available in Pakistan.

If iTunes recognizes it, then it is a "real" iPhone.

nasirfromsadiq abad wrote:

Please tell me how to check when it is activated

How to check what?

What is it you're trying to figure out?

You can't. Since it's physically impossible to purchase an iPhone from any authorized source in Pakistan, you are, by definition, buying a used phone.

If you're concerned and don't trust the seller, then don't buy it.

No.

You can check to see if it's activation locked here: https://www.icloud.com/activationlock/

And you can check the warranty status here: https://selfsolve.apple.com/agreementWarrantyDynamic.do

Although, the warranty doesn't do you much good as even if it is under warranty, the warranty is only valid in the country where the phone was originally sold. You can not get warranty service or support in Pakistan.

What is terrible?

Apple does not do business there. There is nothing anyone here can do about it. This is a user forum.

You can actually use the links provided to check the validity of the phone, or you can keep posting snippets of a sentence that mean nothing. Your choice, but we can't mysteriously identify the phone for you.

Im buying a Iphone 6plus 16GB by a person saying that it is brand new and unlocked.

So How can I check if it is brand new or used for how long already? and is it unlocked or not without having many different provider sim cards?

A "person" is not an authorized source. There is no way to know the history of the phone, or where it is/was intended to be sold at. There would be no way to verify that information. The serial number could give you warranty status as stated earlier in this thread, but no way to identify if it is unlocked or not. The model number inside the phone would tell you where it was intended to be sold at, but the phone would have to be activated to do that. If you want to be especially sure about your phone, then purchase it from Apple or an Authorized reseller, in the country you want to use the device in.