Documents that have to be retained for 6 years within accounts?

This question probably relates to income tax act 1961 India. Any authority on tax laws will be a competent person to answer this question.

• However, so far I know the documents of income and expenditures on the basis of which income tax returns filed every year by a person is to be retainedfor six years after the date of final assessment is made. But in some cases the income tax authorities do you believe the statement of accounts submitted by a person and put the case under scrutiny query and the period of premiums