The deadline to exchange the current currency is through March 2017. I am sure there will be folks who would accept the old currencies at discount if they think they can get it exchanged at the bank without getting Government scrutiny. However, this will only work if you have small amount of black money. There are rich folks in India who have millions of Rupees in black currency and there is no way they will be able convert all that cash without declaring it and paying tax on it.