Bins under the floor
Under the turret floor of the Tiger 1 there are two large, open storage bins. The one on the right side is designed to hold six projectiles. The bin on the left side is just a box for the crew's possessions.
Looking down into the right-side bin in a museum vehicle, we can see wooden brackets (arrowed).
This is another right-side bin, but in better condition. Here we can see that the bin has wooden panels on its ends so that the shells will not bump the metal. The wooden brackets on the floor are shaped to hold the shells, and belts with buckles are firmly attached to the wall so that the shells can be locked down.
Bins in this kit
Model kits frequently make a mistake in this area. They assume that the left-hand bin would hold shells. That is highly unlikely in real life, because that bin lacks the brackets and straps to hold the explosive shells safely.
For example, this old kit from Rye Field Model has shells in both of the bins, and no straps to hold them. Some of them are facing the wrong way.
In more recent kit releases, Rye Field apparently omit the shells from their left-hand bin. But the shape of their bin part is wrong.
Trumpeter also make mistakes here. They assume that the straps are not connected to the bin. They also put ammunition in the left-side bin. Trumpeter's right-side bin lacks the brackets and panels of the real one.