The yields are quoted net of a 10 percent withholding tax on interest.
The debt office said it sold 35 billion rupees of bills after offering 20 billion for rollover at the auction, including 30.8 billion rupees in 12-motn bills.
Also sold were 2.0 billion in 3-month bills and 3.0 billion rupees in 6-month bills.
At an auction Wednesday, bond yields also dropped.