I think there might be a small mix-up in the term. In Jain practice there are two common but different things that people might mean by similar words:

• Navkārī/Namokārī (Namokar Mantra): the central prayer in Jainism, praising the arihants, siddhas, acharyas, sādhu-s, and sādhuṇī-s. If you mean this, you can prefer it by reciting the Namokar mantra regularly (in morning and evening puja, or before meals), with a calm, reverent attitude and correct pronunciation. Digambar and Śvetāmbar traditions both venerate this mantra, though some editorial details (like sequence or accompanying stotras) may differ between the two communities.
• Navkārṣī or Navkarsi vrata: if you are referring to a vrata or practice associated with ninefold observances, note that Jain texts describe various vrat or discipline practices, and exact rules can differ by Digambar vs. Śvetāmbar lineages and by regional tradition.

Since “Navkarsi” isn’t a standard, universally fixed term across all Jain traditions, could you please confirm which of the following you mean? 1) Namokar Mantra (Navkārī) — the nine-greats prayer; or 2) a ninefold vrata/practice (Navkārṣī) you’ve encountered in a specific Jain tradition or region?

Once you confirm, I’ll give you a precise, tradition-faithful explanation (including the original wording if you request it, and how it’s interpreted differently in Digambar and Śvetāmbar lines).