Some of it may be salvageable, but there’s no guarantee. The film that was out in the open is almost certainly exposed. The portion still tightly wound on the spool may have some protection, since room light usually won’t penetrate many layers, but the outer wraps and edges are likely fogged.

How bad it is depends on the light level, how long it was exposed, and the film speed. Faster film fogs more easily. Since you don’t know the film type or ISO, it’s risky to rely on it for anything important.

Best option: cut and develop a short test strip from the outer part of the remaining roll, then another from deeper in the spool, and compare fogging. If the inner layers look usable, you might save some of it for experiments. But because the film’s identity and history are unknown, it’s wise not to trust it for critical work.