Got a solution.
XCode -> Archive -> Select project in Organizer -> Show in Finder -> Show Package contents -> Products -> Applications -> "Product.app".
Create a folder named "Payload" -> Put "Product.app" with in "Payload" -> Compress "Payload" -> Get "Payload.zip" -> Change name to "Product.ipa".
For installing instructions in iTunes 12.7.0 please follow this link.