Answer

In Kāusagg / Kāyotsarga, the main words commonly chanted are:

“Namo Arihantāṇam”

or the full Navkār Mantra:

Ṇamo Arihantāṇaṁ
Ṇamo Siddhāṇaṁ
Ṇamo Āyariyāṇaṁ
Ṇamo Uvajjhāyāṇaṁ
Ṇamo Loe Savva-Sāhūṇaṁ

Explanation

During Kāusagg, one keeps the body still and focuses the mind on the soul. Depending on the tradition and ritual being performed, people may chant:

• Navkār Mantra
• “Namo Arihantāṇam” repeatedly
• Other prescribed mantras or sutras given in that specific ritual

In many daily practices, especially while doing a short Kāusagg, devotees silently repeat Navkār Mantra or focus on Arihant Bhagwan.

Spiritual Understanding

Kāusagg means giving up attachment to the body for some time. The purpose is not only chanting words, but to become steady, calm, detached, and aware of the soul.

Takeaway

For simple Kāusagg, you can respectfully chant Navkār Mantra or repeat “Namo Arihantāṇam” with full concentration and devotion.