KJV
John 1:42 And he brought him to Jesus. And when Jesus beheld him, he said, Thou art Simon the son of Jona: thou shalt be called Cephas, which is by interpretation, A stone.
RSV
42 He brought him to Jesus. Jesus looked at him, and said, "So you are Simon the son of John? You shall be called Cephas" (which means Peter).
In English transliteration of Hebrew and Aramaic, the "K" is rendered either with "K" or with "C". Thus you will sometimes see tanakh and sometimes tanach. It is purely a matter of preference.