Short answer: No. There is no “parna” (formal fast‑breaking) for ekasana.

Explanation:

• Ekasana is taking only one meal in a day; it is not an anashan (complete fast). Parna applies to upavasa and longer fasts (e.g., beasana, attham, chhath, aththai, masakshaman, varsitap), where food is totally avoided and then formally resumed at the prescribed time.
• If you had taken a niyam (vow) to do ekasana for a number of days, you simply conclude the niyam respectfully—usually with pratikraman/samayik and guru‑vandan—and from the next day you may resume your regular aahar. This is not called parna.

Notes (common practice in both Shvetambar and Digambar traditions):

• Ekasana means one sitting, one place, within prescribed time (before sunset), with proper maryada.
• Boiled water rules and time windows follow your tradition’s standard aushadh/boiled‑water discipline.
• Ending a multi‑day ekasana niyam is called niyam‑chhed/niyam‑utaar, not parna.