Presumably the negatives, but not the pictures, as this is intended to scan only negatives. You'd probably have better luck with a cheap flatbed scanner that comes with adapters for slides and negatives. (I've used both dedicated film scanners and flatbed scanners to scan thousands of rolls of film and prints taken over a span of 50 years.)
No. 4x6 negatives are large format and requires a different type of scanner (flat bed). If you look at the photos the 35mm roll slides into the device so you can’t fit a larger format sheet into the feed.