As per the below article NRI cannot open new PPF account, but they can continue with their old PPF account.
Link -
http://www.moneycontrol.com/news/nri...nt_217589.html
* SAFE
Self Appointed Financial Expert
NRI cannot open a fresh PPF account. However if he has opened a PPF a/c before he became an NRI, that PPF account can be continued. And he can use you Non Resident Account for investment purpose.
Thank you guys.