Following procedure should be followed:-

1.NRI / PIO should open PIS account with Bank.

2.NRI / PIO should open NRI repatriable demat account.

3.Obtain copy of RBI permission issued by bank.

4.NRI / PIO should authorise broker and or its authorised person to
submit the contract note, collect the payment / give the cheque to
 bank.

5.After carrying out the trade, submit contract note to the bank of
 NRI /PIO client and collect / make the payment.

6.Before carrying out purchase transaction check the FII limit in the
scrip and adhere to the limit.