In Jain Dharma, Navkar is one Mahā‑mantra (Navkar / Namokar Mahāmantra).

From this one mantra:

• It has 5 main lines (5 padas) – each of these 5 lines can itself be recited as a separate small mantra (for example, only “Namo Arihantāṇam”).
• With the 4 explanatory lines, some texts speak of 9 padas in total.
• Every akshar (letter) of Navkar is also considered very powerful, so saints say countless other mantras can be “derived” from it.
• In popular Jain talks you may hear that 84 lakh (8.4 million) mantras come out of Navkar Mantra – this shows its greatness, but this number is more traditional belief, not a strict list from scriptures.

So, in simple words:

• Basically there is only one Navkar Mahāmantra.
• Inside it, 5 main lines (and with chulikā, 9 padas) are respected like many mantras, and tradition praises it as the source of innumerable mantras.

For a very simple explanation of Navkar Mantra you can read here