、。
To tell the truth, he's a famous lawyer.
Literal
True [possessive-の] thing [object-を] say [conditional-と], he [topic-は] famous lawyer.
本当のことを言うと ('if I tell the truth') is a discourse-opening frame used to introduce a candid revelation — typically something the speaker has been holding back. The と here is conditional ('if/when [I say]'). Useful for prefacing both impressive disclosures and embarrassing confessions; the frame itself is neutral.