Daily Square Off is not allowed for NRI i.e. intraday trades are not allowed for NRI clients.
Clients can trade only on Delivery basis.
All contract notes of either Buy or Sell has to be reported to Authorised Dealer ( PIS Banker) within 24 hours to transactions.
Every sale transaction will be credited to client Banks account Net of tax. Hence for every sale transaction capital gain will be calculated by a CA. As per current laws for long term capital gains, Tax rate is nil & for short-term capital gain, tax rate is 15.45%.

No, NRI Investor has to take delivery of shares purchased and give delivery of shares sold. Short Selling is not permitted.

Yes, NRI can purchase shares or convertible debenture of an Indian Company through stock exchanges, under the portfolio investment scheme on repatriation and /or non-repatriation basis.

Non-Resident (External) Rupee (NRE) is a Rupee account using which the funds can be repatriated. It means that the account can be started with funds which can be either transmitted to abroad or from abroad.
Non-Resident Ordinary Rupee (NRO) is a Rupee account which can be initiated with funds which are remitted either from abroad or are generated in the country itself. The striking feature is that the amount in this account is non-repatriable. However, funds in NRO account can be repatriated based on the rules that are being followed at the time of repatriation.

NRI Income in India: All NRIs that have income earned in India will be taxed and should file for tax returns annually. For an NRI, it is not required to file for tax returns on investment gains if the tax was deducted from it in the beginning.