In Jainism, the term "64-handed Devi" generally refers to a form of the goddess Padmavati or Ambika depicted with multiple arms, often in tantric or yakshini representations. However, traditional Jain worship emphasizes devotion to the Tirthankaras and not to goddesses or deities in the same way as in some other Indian traditions.

Some Jain sects, especially within the Shwetambar tradition, may have rituals or pujas involving yakshis (female attendant deities) like Padmavati Devi, who is sometimes depicted with multiple arms—occasionally as many as 64, symbolizing her manifold powers and abilities to protect devotees. These forms are more common in tantric or esoteric Jain practices, which are less emphasized in mainstream Jainism.

Sadhu (monks) in Jainism strictly follow the path of renunciation and generally do not perform elaborate pujas (ritualistic worship) involving idols or images, especially not to yakshis or goddesses. Their practices center on meditation, study, and self-discipline. Ritual worship with offerings and idol adornment is typically performed by laypersons (shravaks/shravikas).

If you are referencing a sadhu performing puja in front of a 64-handed Devi, this is not a standard or orthodox Jain practice and may be a local or folk tradition, or even a misunderstanding. In classical Jain doctrine, monks are expected to avoid all forms of ritualistic worship involving material offerings and instead focus on spiritual purification and self-realization.

In summary, the "64-handed Devi" refers to a form of a Jain yakshi goddess, but monks do not traditionally perform such pujas in orthodox Jain practice.