Below is a list of taken and available characters from the film. G1 'Bots and 'Cons are not listed, just due to the fact that they didn't appear in the movie. Still feel free to apply for them!

Autobots:
Optimus Prime -- (OPEN)
Bumblebee -- Shouri
Ironhide -- AleksandraF
Ratchet -- Silverdragon868
Prowl -- Lune Nightingale


Decepticons:
Barricade -- Shouri
Starscream -- (OPEN)

Humans:
Sam Witwicky -- (OPEN)
Mikaela Banes -- (OPEN)
William Lennox -- (OPEN)
Simmons -- (OPEN)

Paragon Defense Engineering:
(No characters available at the moment, check back in the future!)