It was one of the largest sums ever spent on a license plate, although still lower than the $14 million record set in 2008 by an Abu Dhabi businessman.
However, Sahni realised that he can't go out in public without people stopping him and asking to take a photo -- and some aren't impressed, accusing him of wasting his money.
"It's hard, people giving comments without knowing the type of person I am," Sahni told CNNMoney. He described himself as "a simple man."
The single-digit plates now adorn two of his six Rolls Royce cars.
According to CNNMoney, it's also not the first time Sahni has spent serious money on a license plate. He secured a No. 9 plate with a winning bid of 24.5 million dirhams ($6.7 million) at a government auction last year.
Sahni says he sees the hefty license plate purchases as his contribution to the public coffers. He says he believes the money will go to charity and toward improving the city's infrastructure.
"I believe in giving back," he said. "This city has given me a lot."