A term denoting double-barrel respect. It ain't enough to call him a sir! Ji is the respectful suffix in Hindi added to anything - madamji, driverji...
Origins unknown, but first popularised by oily North Indian property dealers/ estate agents.
Done deal, Sirji,,,agreement ready on stamp paper
You're giving me bad words and I'm still respecting, Sirji
Added 2011-07-13 by Bal-cao