Yes, you should be able to lock your YFI for Veyfi on the 30th of November. This is because the YFI token is currently in the process of being locked in the Veyfi platform. This process is expected to be completed by the 30th of November, which will allow you to lock your YFI tokens in order to receive the Veyfi tokens. Once the process is completed, you will be able to lock your YFI tokens and receive the Veyfi tokens in exchange. It is important to note that the process may take longer than expected, so it is best to check the progress of the process before locking your YFI tokens.