To restore messages on your device from your JioCloud account, open the hamburger menu and click on ‘Messages’. Here you will find a list of messages that have been backed-up in your JioCloud account. Go to menu (on top-right corner) click on ‘Restore’. Here you will see list of devices from which you have backed-up messages as well as an option to restore deleted messages. You will also be prompted to back-up the messages on the new device before proceeding. 

Please Note: When you start restoring messages on the device, if there are messages on the device that are not backed-up on JioCloud then those messages shall be deleted. So please ensure you backup messages from the new device also before initiating the message restore.