udChalo credit is a form of virtual currency within the udChalo system that holds the user's funds for bookings and transactions. If something goes wrong with a booking, the refunded amount will credit in udChalo credit for the user's convenience in making future transactions.
However, you can also transfer the amount anytime in any of your bank accounts.
For more information, you may refer to this article: Why udChalo credit? What are the benefits of it?