If you control a “Neos” Fusion Monster that is owned by your opponent and you select it with “Contact Out”, the “Neos” Fusion Monster is returned to its owner’s Fusion Deck (your opponent). You will still Special Summon the Fusion Material Monsters from your Deck.
“Contact Out” can still be activated when the Fusion Material Monsters written in the text of the “Neos” Fusion Monster are not present in the Deck of the controller of the “Neos” Fusion Monster. In this case the “Neos” Fusion Monster is returned to its owner’s Fusion Deck, but no monsters will be Special Summoned.