India Post's Public Provident Fund is a long-term investment option offering tax-free returns. According to News18 report, at 7.1% interest, investing ₹12,500 monthly (i.e., ₹1.5 lakh yearly, maximum permissible limit) for 15 years can grow to ₹40.68 lakh, including ₹18.18 lakh interest. Partial withdrawals are allowed after five years, and investors can take loans against their PPF balance.