Most of your doubts got answered here.
Who is an NRI?
According to Sec. 6(1) of the Income Tax Act, an individual shall be a resident in India in any financial Year if he
a. Is in India in that Financial Year for a period or periods totaling to 182 days or more Or
b.Has been in India within the four preceding years for a period or periods totaling to 365 days or more and for a period of 60 days or more in that Financial Year.
Who is a PIO?
A citizen of a foreign country (other than a citizen of Bangladesh or Pakistan) is a PIO if:
He/She at any time held an Indian Passport. OR
He/She or either of his parents or any of his/her grandparents was a citizen of India; OR
Spouse (not being a citizen of Bangladesh or Pakistan) of an Indian citizen (a) or (b) above.
What are the products offered to NRI?
NRI can invest in the following products.
Equity trading on BSE and NSE
Derivatives trading on the NSE
IPO
Portfolio Management
Investments in Mutual Funds
What steps an NRI needs to take to start investing in the Indian Stock Market?
Acquire Pan Card or provide existing PAN Card Number.
Establish NRE/ NRO Bank Account - Savings and PIS account with designated bank which is approved by RBI for this purpose.
Establish Demat account with broker and start trading
What type of saving bank account(s) can be opened by an NRI or PIO in India?
Any NRI/PIO can open two types of savings accounts with any bank in India. They are NRE and NRO bank accounts.
What is a NRE account?
A NRE bank account is an external saving bank account opened for Non resident Indians. This is why it is known as Non-Resident External account. Since it is an external account, any monies lying in NRE account can be taken outside the country or in other words, the monies lying in NRE account are fully repatriable. This money can be converted into any foreign currency at the behest of the account holder and can be remitted outside the country.
What is a NRO account?
A NRO bank account is an ordinary saving bank account opened for Non resident Indians. This is why it is known as Non-Resident Ordinary account. Since it is an ordinary account i.e. as good as a normal saving bank account, monies lying in NRO account cannot be taken outside the country or in other words, the monies lying in NRO account are not repatriable.
Can money be transferred from NRE account to NRO account?
Yes money can be freely transferred from NRE account to NRO account.
Can money be transferred from NRO account to NRE account?
No, money cannot be transferred from NRO account to NRE account.
What is the status of NRO/NRE accounts on the return of the account holder to India?
RBI has advised banks to re-designate such accounts as resident accounts on return of the account holder to India.