Those over the age of 65 years and people infected with coronavirus or suspected of having contracted the infection will be allowed to vote by postal ballot after the government amended the Conduct of Election Rules, 1961.
In several health advisories, people over the age of 65 have been asked not to venture out as they are particularly vulnerable to catching the highly contagious virus.
The move comes ahead of the Bihar elections. The coronavirus pandemic has brought political activities to a juddering halt.
Earlier, casting votes through postal ballots was available only to armed forces and officials assigned poll duties.
In February, Delhi became the first state to experiment with postal ballots, extending the facilities to those with severe disabilities or above the age of 80 years.
The elections to fill 19 vacancies in the Rajya Sabha in nine states were originally to take place in March but were deferred after the outbreak of the Covid-19 pandemic. They were then held in June and arrangements were made to allow members who are unwell to vote through postal ballot.