Can anyone explain section 80cca of income tax act,1961

I am very confused in deduction allowed u/s 80CCA of Income Tax Act, 1961

According to this section , deductions will be allowed only after AY 1988-89 to upto AY 1992-93 in NSS or LIC

What whould happen if such National Saving Scheme (NSS) had been taken before AY 1988-89 or after AY 1992-93.

Does Deductions availabe Under Section 80C appies to such NSS ??