In Jainism, there is no fixed or scripturally mandated number of Jain sadhus (munis) or sadhvis for performing rituals like pithi (a pre-renunciation or celebratory ritual, often before diksha, the initiation into monkhood). The presence of Jain monks or nuns during such ceremonies is considered auspicious, and families often invite as many as are available or willing to attend, based on local traditions and the size of the event.

The pithi ceremony itself is a social and religious function performed by the family of the person who is about to take diksha, and it is not mandatory for a specific number of munis to be present. However, the blessings and presence of Jain ascetics are highly valued.

In summary:

• There is no fixed number of Jain munis or sadhvis required for pithi or similar rituals.
• The presence of any Jain sadhu/sadhvi is considered auspicious.
• The specific practices may vary based on local customs and community traditions.

If you are planning such a ceremony, it is best to consult with the local Jain sangh or temple authorities for guidance based on your sect (Digambar or Shwetambar) and community practices.