Can rubber hoods be used on a different brand of brake levers? The rubber hoods on my SRAM levers have started to tear. However, locally there are only a couple of Shimano rubber hoods.

Can they fit and what should I pay attention to?
No. The rubber hoods are designed to closely match the lever's shape and are not stretched when installed. There are some third party replacement hoods, but they too are designed to fit specific lever models.

If you can't find the correct part locally, there are many mail order shops that have good selection of even uncommon or old spare parts.