which are the metallic parts in the androids? and those cybe

which are the metallic parts in the androids? and those cybernetics?

BRAIN HEART AND MAYBE THE SKELETON? is it true?

If you're inquiring as to the physical make-up of replicants, there's actually a thread in the "Android Science" board that discusses that very topic. To give a short answer: No one knows for sure. But most agree that replicants are either mostly organic with minor mechanical parts or entirely organic (literally "living machines").

probably an answer could be found in what Holden tells Deck in the first hospital scene, before the dialogue changed:

HOLDEN: They do a routine autopsy on the one that got aired and.. whaddya know? A skin job, one of the ones that busted out! Top drawer replicant.. combat type.. Nexus six.

DECKARD: Pretty sexy, the sixes.

HOLDEN: Sexy! Three hours into the autopsy they still think they're cutting up a human. No marks, nothing.