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