Conversion of black money to white.
You can go to Post offices with with black money even without PAN buy Kisan Vikas Patra of any amount and you get double the amount in 8 years.
Full details go to link below:-
http://www.thehindubusinessline.com/banking/no-pan-requirement-for-investment-in-kisan-vikas-patra/article6610793.ece more