There is no rule for individuals but for businesses need to keep books for at least 6 years.
For how many years books of accounts are required to be preserved:
Every year the record of books of accounts grows up and the cupboards filled up more and more. Every assessee wants to know for how many years he should keep the records of his books of accounts. Rule 6F(5) provides that the books of accounts and other documents are to be kept for at least 6 years from the end of relevant assessment year. That means from the assessment year 2009-10 one should keep books of accounts upto the assessment year 2003-04 i.e. books of accounts of financial year 2002-03