PPF 1.5L deduction, 50% withdrawal cap

PPF comes with triple tax benefits: what you invest (up to ₹1.5 lakh per year) qualifies for a tax deduction under the old tax regime, the interest you earn, and your final withdrawal are tax-free, while the contribution deduction is available under the old tax regime.
You can make partial withdrawals after five years, but only up to 50% of the lower of the balance at the end of the fourth year before withdrawal or the balance at the end of the previous year.

Five-year PPF closure for life-threatening illness/education

You can close your PPF account after five years from the end of the year in which the account was opened if there's a life-threatening disease affecting the account holder, spouse, or dependent children, or higher education need,
but there's a catch: a 1% cut in your earned interest from the rate at which interest has been credited from time to time since the date of opening, or from the start of the current five-year block period, as applicable.