You can solve this in 2 ways. First one, You can simply un select the product which are not to be displayed in the Fruits page through Manage Product->[required product]->Categories.Here select the Mango and unselect Orange.
And the next one, You can get the Product Collection and through Mage::getModel(catalog/category)
you can get the IDs Of all the top categories and child Categories. Asusal the product which is not to be displayed contains the top category ID and its own ID. Here you can give the ID as statically and remove them.