It’s possible to complete this action from Magento product grid provided you have an option to sort products by category (this feature is missing in Magento out-of-the-box but can be added through customizations or extensions like Extended Product Grid).
In order to set products from a particular category to Pre order, you need to apply a mass action called “Update Attributes”. On the inventory tab you will need to choose “Allow Pre-Orders” in the backorders field:
It is a simple product status which is taken into account. This means that the stock status of a configurable product, for example, will depend on the status of the simple product which is currently selected.