In Jain tradition, “Devananda womb 82.5” usually refers to this point:

• According to Śvetāmbara scriptures,

the soul of Bhagwān Mahāvīr first entered the womb of a Brahmin lady Devānandā.

• He stayed in Devānandā’s womb for about 82½ days.
• After that period, by the order of Indra, the deity Hari‑Naigameśin transferred the embryo from Devānandā’s womb to Mātā Triśalā’s womb, the queen of King Siddhārtha.
• From Triśalā’s womb, Mahāvīr finally took birth.

Difference of traditions

• Śvetāmbara: Accept this garbha‑parivartan (embryo transfer) story and the stay in Devānandā’s womb for ~82½ days.
• Digambara: Do not accept the embryo‑transfer episode; they hold that Mahāvīr was conceived directly in Triśalā’s womb only.

So “Devananda womb 82.5” is a short way of pointing to the Śvetāmbara belief that Mahāvīr’s soul stayed about 82½ days in Devānandā’s womb before being divinely transferred to Triśalā.

You can read a bit more on Mahāvīr Janma Kalyāṇak and garbh‑parivartan here