1 Hong Kong dollar = 6.69754754 Indian rupees
As of 16Feb09 USD1 was worth INR48.60.
It varies, so use the link I posted below for the current exchange rate.
One billion dollars [1,000,000,000] in US currency would equal 46,180.000,305.18 Indian Rupees[INR]
According to today one dollar is equal to 44 rupees.