If you mean applying for a new patent with multiple existing product combinations, it is a combined invention patent. Whether you can apply for a patent depends on whether the technical effects of several product combinations can support each other. If it is only a simple structural combination, you can't apply for a patent.
For example, adding an eraser to the tail of a pencil needs to be used alternately at work, and the combination can achieve the function of being convenient for users to use and carry. At this time, the combination is creative and practical, and you can apply for a patent.
On the other hand, if you add things that have nothing to do with your work, such as electronic watches and thermometers, it is not practical and you cannot apply for a patent.
The patent of composite structure can be applied for invention patent or utility model patent. Invention patents have higher requirements for creativity, while utility models have lower requirements for creativity and pay more attention to practicality.