When zoro will be with robin?

Eiichiro Oda, the creator of One Piece, has specifically said that there will be no romance in One Piece and so there will be no couples. Therefore, Zoro and Robin will never "get together".

If you've noticed, no crew member actually expresses any romantic feelings towards each other, except for Sanji, who acts on lust alone and will do so for any pretty face regardless of personality.