1) Che c'e` ora? (English: what do you want now?)
has a shade of being annoyed in the meaning.
2) Che ora c'e`? (ha no meaning, we never use this form)
3) Che ora e`? (Eng.: What's the time ?)
4) Che ore sono ? (Eng.: What's the time ?)
5) Mi dici l'ora ? (Eng.: Tell me the time)
For some reasons, we usually prefer forms (4) (plural!) and (5) (singular!), to which you could alway add /per favore = please/