I'm presuming you don't know the make/model of the floor tom itself. Such knowledge would be revealing, unless the bracket was replaced at some point with a different brand.
I wouldn't fret too much. You should be able to locate a universal option, though it might not be a perfect match. Gibraltar would be a good place to start. They make an assortment of high-quality hardware adaptable to most brands.
If you post a pic of the drum, or even the whole kit we may be able to identify the brand.