If you want to crop a lot of images to exactly the same size AND position, in other words if you want to crop off say, 10% top, 15% bottom from every photo, then View NX2 will do it for you.
It is a free download from Nikon which also allows you to edit your raw files as well as JPEGS.
All you do is select all the pictures you want to crop in the Browser window, click on the Edit button, select Free Crop from the RH Crop menu, click and drag to get the crop you want on the single photo showing and that crop will also be applied to all the other photos you have selected.