The minimum age for being eligible to vote in the Indian Elections was reduced from $21\text{years}$ to $18\text{years}$ in the decade of -

The voting age in India was reduced from $21\text{years}$ to $18\text{years}$ by the 61st Constitutional Amendment Act. This amendment was enacted in 1988 and came into force in March 1989, which falls under the decade of the 1980s.