Answer

If you mean Siddhi Tap, it is a Jain fasting and self-discipline observance done to purify karma and progress spiritually. Its exact maryada can vary by sangh and guru, so the proper way is always to follow your own guru’s guidance. ( jainknowledge.com)

Explanation

A common form of Siddhi Tap is:

• Day 1: Upvās
• Day 2: Ekāsan
• Day 3: Upvās
• Day 4: Ekāsan
• Day 5: Upvās
• Day 6: Ekāsan
• then 3 days of attham or 4 days of atthai at the end. ( jainknowledge.com)

Another well-known form is:

• 3 days attham
• 1 parṇā
• again 3 days attham. ( jainknowledge.com)

During the tap, devotees usually keep:

• Pratyākhyān / Pachchakkhān
• Samayik
• Svādhyāy
• Pratikraman
• simple dāna and seva
• extra care in ahiṁsā and restraint. ( jainknowledge.com)

Food and water rules also depend on maryada, but commonly:

• On upvās days, no food is taken.
• On ekāsan days, only one simple meal is taken before sunset.
• Some follow Ayambil-style rules on eating days. ( jainknowledge.com)

Spiritual Understanding

The main purpose of Siddhi Tap is not only physical fasting. It is meant to reduce attachment, increase inner calm, and strengthen spiritual discipline. The outer tap becomes meaningful when the mind stays शांत, संयमित, and जागरूक. ( jainknowledge.com)

Takeaway

In simple words, Siddhi Tap is a serious Jain tapasya of fasting, restraint, and purity. If you want to observe it, the most important thing is to follow the exact maryada of your sangh or guru. ( jainknowledge.com)