The return or exchange period for products varies depending on the marketplace platform (such as Flipkart, Myntra etc) and the specific return policy they have in place. Typically, these policies are detailed on the platform's app or website under the returns and refunds section.
You can check the return or exchange period specified by the marketplace platform from which they purchased the product. This information is usually available in the order history or transaction details and is also available on the product description page.
