In Jainism, when people say “Omkar Mantra” they generally mean the Namokar (Navkar) Mantra, because its essence is also expressed in the short sacred syllable “Om” (A-U-M) as a summary of the Panch Parmeshti.

1. Full Namokar (Navkar / Omkar) Mantra – original text

In Prakrit:

णमो अरिहंताणं णमो सिद्धाणं णमो आयरियाणं णमो उवज्झायाणं णमो लोए सव्वसाहूणं ॥

एसो पंच नमोक्कारो, सव्व पावप्पणासणो । मंगलाणं च सव्वेसिं, पढमं हवई मंगलं ॥

Transliteration:

Namo Arihantanam Namo Siddhanam Namo Ayariyanam Namo Uvajjhayanam Namo Loe Savva‑Sahunam

Eso pancha Namokkaro, savva‑pavappanāsano Mangalanam cha savvesim, padhamam havai mangalam

2. Simple meaning (arth)

• Namo Arihantanam – I bow to the Arihants (omniscient beings who have destroyed inner passions like anger, pride, deceit, greed).
• Namo Siddhanam – I bow to the Siddhas (liberated souls, completely free from birth and death).
• Namo Ayariyanam – I bow to the Acharyas (head monks who guide the sangh).
• Namo Uvajjhayanam – I bow to the Upadhyayas (spiritual teachers who explain the scriptures).
• Namo Loe Savva‑Sahunam – I bow to all sadhus and sadhvis (monks and nuns) in the whole universe.

Summary lines:

• Eso pancha Namokkaro, savva‑pavappanāsano

This five‑fold bowing destroys (helps in destroying) all sins (paap).

• Mangalanam cha savvesim, padhamam havai mangalam

Among all auspicious things, this is the first and foremost auspicious one.

3. Why it is called “Om / Omkar Mantra”

In Jain tradition, the five main salutations are sometimes shortened symbolically as:

• A – Arihant
• A – Ashariri / Siddha
• Ā – Acharya
• U – Upadhyaya
• M – Muni (Sadhu)

Together, A+A+Ā+U+M = “Om”, so “Om” is a brief symbolic form of the Namokar Mantra, not a separate worldly wish‑fulfilling mantra.

Both Shwetambar and Digambar accept the Namokar Mantra as the main Omkar Mantra. Only small pronunciation differences exist; the meaning and spirit are the same.

For more simple explanation of Namokar Mantra you can read here