i have been a seafarer since 2003 dec and have sailed in various ranks all on foreign companies and in international waters.  However have not always been able to complete my NRI days of 183 days for all the financial years.  So far I have not been filling my IT returns.  Now I am planning to buy a property worth 35 lakhs.  I am worried that this might get me into the IT scanner.  Kindly advice on

1. How many back years should I account for, while starting to file IT returns.

2. What documents will be required to show my NRI status.

 

Any experience shared from my fellow seafarers will be greatly appreciated.