In Jain dharma, especially for a satvi (a fully vowed Jain nun), physical contact with a male ascetic is generally avoided. A hug from a sadhu (a male monk) would typically be considered inappropriate because it involves close body contact, which is avoided to maintain purity of vows and sense-control.

How to respond gracefully and in line with dharma:

• Create respectful distance: step back politely and keep a calm, composed demeanor.
• Use a traditional, respectful greeting: clasp hands in namaskara (or bow with folded hands) and offer a quiet, courteous smile.
• Avoid physical contact or personal closeness: do not reciprocate the hug; maintain boundaries in line with vows of celibacy and discipline.
• Gentle redirection if needed: softly say that you are following monastic rules and would prefer not to have physical touch.
• Seek guidance if the situation repeats: inform a senior nun or a supervising monk if you feel uncomfortable or unsure how to respond.

Key point: the aim is to preserve self-control, equanimity, and the integrity of your vows while showing courtesy and respect to the other person.

Note: If you’d like, I can tailor this to a specific Digambar or Shwetambar context and give wording in a traditional salutation.