Tin is a metallic element that shows up in small amounts in the environment and some foods. Scientists have not found any biological function for it in the human body, so it is not considered an essential nutrient.
Some supplement makers stuff tin into mineral blends, then pitch vague benefits for hair, skin, or energy. Clean evidence to back those claims does not exist.
People get trace tin from food without trying. Purposeful supplementation is a bad idea. Large doses turn toxic fast, causing stomach upset and other side effects.