Quick take
Use sediment filtration for particulate rust, but test for dissolved iron before buying. If only one fixture is affected, inspect plumbing before treating the entire house.
Particulate rust
Visible rust flakes can be trapped with sediment filtration sized to the particle load.
Dissolved iron
Clear water that turns orange after standing points toward dissolved iron that oxidizes later. Oxidation plus media filtration is usually the stronger whole-house approach.
Plumbing corrosion
Localized rust can come from old steel or iron plumbing. Replacing the source of corrosion may be more effective than adding a filter.