Finance, Property, Contracts
(1) State property and income are exempt from Union taxation. (2) Parliament may still tax a state government's trade/business activities (and related property/income), to whatever extent it provides by law. (3) This taxing power doesn't apply to trade/business Parliament declares to be an ordinary government function.
This mirrors Article 285 (Union property exempt from state tax) in the opposite direction: states' own property and income are generally protected from Union taxation too - though with a specific carve-out letting the Union tax a state government's genuinely commercial trade/business activities (as opposed to its ordinary governmental functions).
If a state government ran a genuinely commercial business enterprise (as opposed to a core governmental function), Parliament could potentially tax that specific commercial activity under this article's exception, even though the state's ordinary governmental property and income remain untaxed.