Maria - We may need a bit more data on the type of staining as a reddish, brown tint typically is the result of having iron in the water. The type of cleaner you select may be dependent on the source of the stains. Using a type of cholorine tablet in the toilet tank will allow a gradual dose of treated water to sit in the bowl. 2000 Flushes is a well known cleaner if you are looking for the gradual release and continual cleaning rather than a 1-time hard scrub fix. A more abrasive cleaning solution may be a CLR (Calcium Lime Rust) option as I linked for you below.