As per Act No. 23 of 1968, Dated 16th May, 1968 PPF (Public Provident Fund) Scheme was introduced by Government of India. Public Provident Fund Act, 1968 approved by Parliament of India to come into force.
Important thing is that, PPF account could not be attached with any court order against any debt or loan.
Since PPF Scheme is backing by Govt. of India, assured returns can be expected. Every year before April 1st New Interest Rate are announced and based on that returns of that financial year can be calculated.
Even though the rate of returns may be lower than Equity market returns, PPF Returns are stable and secure while equity returns are not stable and secure. It is advisable to add PPF in your investment Portfolio to average your returns in case of any equity losses.
PPF Investment is suitable for Retirement Planning and Children Future Planning which needs funds at any case at a particular time.
Of course inflation risks may be there, But the long term compounding and three levels of Tax Exemptions surely gives you positive returns.