Do crocodile have any rudimentary gills because they were evolved by a fish named tiktaalik?

Regardless of the presumed relationship to tiktaalik, you will find gill slits to be present in all vertebrates. In reptiles, the slits would not persist past the embryonic stage but, the crocodiles' jaws were derived from the gill arches. Look up "Ontogeny recapitulates phylogeny."