
Actually, I am not sure whether the syncing itself has deleted the camera roll photos, to the best of my knowledge, every time you choose to sync your iPhone to iTunes, there should be an iTunes backup file created from which you can restore your lost photos through restoring your lost iPhone with the iTunes backup file. The camera roll pictures cannot be recovered selectively if you choose to restore from previously created backup file through iTunes. And restoring through iTunes cause data overwriting easily, especially when you are not sure about the time the camera roll pictures were lost or deleted by accident and continued to use your iPhone 6. Newly generated data will be overlapped and wiped out of your iPhone 6 permanently and cannot be retrieved.
However, providing that you have the iTunes backup file, and you don’t need to get your camera roll pictures back to your iPhone 6. There is a solution that can help you retrieve your missing pictures from iTunes backup file selectively and transfer to your computer safely without any loss. That is iFonebox, a piece of third party iOS data recovery tool which is very easy to use. You can accomplishing recovering lost pictures with a couple of clicks.
You can download a free trial version of iFonebox to have a try but you need to pay for the license of the full version, as the trial version can only scan and analyze your camera roll but cannot transfer them to your computer.
Here are the steps about how to recover your missing camera roll pictures from your iTunes backup file.
Step 1: Get it started after you have finished the installation of iFonebox. Click on the tab of Recover from iTunes Backup, by doing so, you have chosen the recovery mode of recovering from iTunes backup file. And you will be presented with an interface listing all the iTunes backup file. Choose one from which you want to export your lost cameral roll pictures

Step 2: Choose Photos to recover and export by clicking on the icon for the photos.

Step 3: Preview all the exported pictures and check whatever you want to recover and transfer to your computer for convenient viewing or alternative backup in addition to iTunes backup file.
