CBDT announced the deadline extension in a circular on Saturday, four days ahead of the original deadline of October 31. 

It's imperative that you choose the correct income tax return form for filing your Income Tax returns. The choice of the ITR form depends on the type of your income and your category as a taxpayer

You aren’t required to file an IT return if your income is below the basic exemption limit--which varies depending on your age and chosen tax regime. Still, filing an ITR helps.