In Jainism, "Athai" refers to an eight-day fast, and "Pachkhan" means a formal vow or resolve, usually recited before undertaking a religious observance. Taking the Athai Pachkhan means making a solemn vow to observe the eight-day fast according to Jain traditions.

A general format for Athai Pachkhan is:

In the presence of Arihant, Siddha, Acharya, Upadhyaya, and all Sadhus, I take a vow that for eight days (Athai), I will abstain from food (and/or water, depending on your chosen type of fast), observe the prescribed rules, and engage in spiritual practices such as pratikraman, prabhu bhakti, and self-study. I will remain vigilant in my conduct, seek forgiveness for any faults, and dedicate the merit for universal welfare.

Example Pachkhan (in simple English): "O Lord Arihant! O Siddha Bhagwan! I take a vow that for eight days, starting from today, I will undertake the Athai fast. I will not consume food (and/or water) as per the rules of Athai, and I will observe the prescribed conduct and disciplines. May I remain steadfast in my vow, and if I err knowingly or unknowingly, I seek forgiveness. I dedicate the merit of this fast towards the welfare of all living beings."

Note:

• The exact wording may differ by sect (Shwetambar/Digambar) and local practice.
• It is best to consult with a Jain monk/nun or a knowledgeable layperson for the proper pachkhan in your tradition and to ensure you are physically and mentally prepared for such an austere practice.
• Fasting should always be undertaken with proper understanding, health considerations, and guidance.

If you need the pachkhan in a specific language (like Gujarati, Hindi, or Prakrit), please specify your preference.