Jaguars eat caiman which are closely related to alligators and crocodiles. They are relatively small sized crocodilians. The average maximum weight is around 88 pounds. The exception is the black caiman which can be extremely large, weighing up to 2400 pounds.
Having researched the question in the title thoroughly it seems to me that jaguars do not attack and eat crocodiles but they do, depending upon the availability, eat caiman. These will usually be small caiman.
Jaguars are known to kill large prey in what is described as a third way namely using their incredibly strong bite to force their canine teeth into the skull of the prey. Jaguars are known to often have chipped teeth for this reason.
Jaguars living on the floodplain of the San Jorge and Cauca rivers in northern Colombia regularly eat caiman. It depends upon the location and the sort of prey that exists in that location.
Jaguars eat a very wide range of prey which varies with geographic location. More than a eighty-five species of prey have been reported. The mean weight of Jaguar prey is 15.6 kg (34 pounds) was maybe lighter than what you might have imagined. This cat seems to prefer peccaries, which are medium-sized pigs found in Central and South America. Another name for this animal is the javelina.