Navkar (Namokar) is a prayer of reverence to the 9 categories of enlightened beings and to the Jain spiritual community. It is not a schedule of fasting. So there is no fixed number of fasts associated with Navkar tapas.

If you were referring to a different practice called “Nav-tap” or to a specific fasting tradition tied to Navkar, please tell me which tradition (Digambar or Shwetambar) or give a bit more context, and I can explain the customs precisely.