I am a Chinese national. I have questions about the Nuffic certificate.

The Nuffic certificate (formerly known as the NESO certificate) is not required when applying for an MSc programme. For the required application documents please see our website
If you have been accepted to TU Delft, this certificate will be necessary for obtaining your student visa. We recommend that you apply for the Nuffic Certificate at least four months prior to your planned departure for the Netherlands. The average processing time is four weeks, but it may take up to two months. Keep in mind that holiday periods and national holidays may extend the processing time. Read more at Nuffic’s website
For information on the Nuffic certificate please visit this website.