A 3-in-1 NRI Account is a stock market investment account designed for NRIs. It consists of NRI Bank Accounts (NRE or NRO) ,
PIS Permission , NRI Trading & NRI Demat Account . Some NRI stock brokers also offer PAN Account opening services. The account is also advertised by some brokers as 4-in-1 account as it includes 2 bank accounts; NRE and NRO for repatriable and non-repatriable investments.
PIS linked NRI 3-in-1 account is mostly offered by banks who also offer stock broking services. The bank NRI 3-in-1 account is offered by top banks in India including ICICI,SBI
Other full-service and discount stock brokers like Sharekhan, Zerodha, and Prostocks also offer an NRI 2-in-1 account (trading + demat account). They have tie-ups with certain banks wherein they help you open bank accounts and link them to their trading and demat accounts.