Choose NRE accounts if you
Want to park your overseas earnings remitted to India converted to Indian Rupees; want to maintain savings in Rupee but keep them liquid; want to make a joint account with another NRI; want Rupee savings to be freely repatriable.

Choose NRO account if you
want to park India based earnings in Rupees in India; want account to deposit income earned in India such as rent, dividends etc; want to open account with resident Indian (close relative)
NRE bank accounts are accounts that hold repatriable money. That is, money in such accounts can be converted back to a foreign currency. NRO bank accounts, on the other hand, are accounts that hold non-repatriable money. Money in NRO accounts will stay as Indian rupees and cannot be readily converted back.
A note about mariners
If an NRI/PIO/OCI is earning income originating in India (such as salary, rent, dividends etc.) he/she is only allowed to deposit it in NRO account. Deposit of such earnings is not permitted in NRE account.
