You can check if your iPhone is Original or Fake

Check iPhone's IMEI Number Even Before Opening the Box

 Go to iphoneox.com and enter the IMEI number, you will get all the details of the phone

 No details will be available if iPhone is fake

You can check the version of the phone by going to About in the settings of the mobile.

 If the device is telling the Android version then the iPhone is fake

If the phone is asking for a Google or other account to sign in, then it is fake

 iPhone interface always asks for Apple ID for sign in