Short answer: No one.

In authentic Jain accounts, Somil (Somil Brahmin) is known for hosting a big animal‑sacrifice yajna where Indrabhuti Gautam and other scholars were present. After Bhagwan Mahavir’s arrival and the ensuing debates, those scholars accepted diksha, and Somil canceled the sacrifice and freed the animals. There is no scriptural mention of Somil Brahmin giving a “moksha paghadi” to anyone. “Moksha” is attained by the soul through its own purity; a “pagdi” ceremony is not a Jain scriptural concept.

For the Somil–Gautam–Mahavir incident, see this simple narrative on JainKnowledge: