Can one organisim be consumer onivore predator and prey?

Yes. An organism that eats another animal would be a consumer and a predator. An organism that eats both other animals and some plant matter would be a consumer, predator, and omnivore. This organism could easily be the prey of another animal, making it all four categories. An example I can think of off the top of my head here is a woodpecker. It eats some other other animals (when it pecks on a tree trunk, it is hunting for insect grubs that live in the wood and eats them); it eats plant matter (it will eat sunflower seeds at a birdfeeder for example); it is eaten by other animals (a sharp shinned hawk could make a fairly easy meal out of an unwary woodpecker for example). There are all kinds of examples. In fact, consider ANY omnivore and you already have your first three categories, and all you have to do is see if that organism is eaten by others, making it prey. Unless it is the rare animal that is at the top of the food chain, it is likely all four of these categories if it is already an omnivore.