Tenure: 15 years, extend indefinitely in 5-year blocks (with/without contributions).
Deposit: ₹500-₹1.5 lakh/year (max also gets full 80C tax benefit).
Tax: Exempt-Exempt-Exempt — deduction at deposit, no tax on interest, no tax at maturity.
Withdrawal: 1st withdrawal after 6th financial year (up to 50% of balance at end of 4 yrs prior). Loan permitted from 3rd to 6th year.
Tip: deposit between Apr 1 and 5th of any month to get an extra month's interest, since interest is calculated on the lowest balance between 5th and month-end.