I with family have 21 hour transit in Kunming and Airline provided me Hotel. DO I need transit Visa?

No, you don't need transit visa because you are eligible for 24-hour free visa. But if you wish to go out of the airport, you need to apply for a stay permit. Here are the steps: Fill an Arrival/Departure Card at the border inspection counter - Get the temporary entry permit stamp or sticker - Claim the luggage (if needed) - Go through the customs.