Can you cook a 25 lb turkey in an oven that is 9 inches from the bottom rack to the heating elements?
9 Inches in height does indeed sound like it might not be enough to fit the turkey in at all. You also need to take into consideration that you need some space around the bird to allow the heat to spread evenly through the inside of the oven. I would generally not try to cook something in an oven that it barely fits in to.

I did a bit of Googling for you and found this semi relevant link where you find a little table with advised sizes for roasting pans compared to turkey weight.