Born in 1954 in Bihar, Prasad started his political innings as a student leader in 1970s organising protests against the then Indira Gandhi government.
The twins are enrolled for voting in the Digha assembly segment under the Patna Sahib Lok Sabha constituency.
Prior to casting his vote Prasad, who was accompanied by his 88-year old mother, expressed the confidence that he will win.
The Congress chief was campaigning for party candidate Shatrughan Sinha contesting from Patna-Sahib Lok Sabha constituency against BJP’s Ravi Shankar Prasad.
The roadshow is seen as a reply to BJP chief Amit Shah and PM Modi's rallies here on Tuesday.
Patna-born Sinha, 73, also the senior-most candidate from the Patna Sahib seat, owns seven vehicles, including one Ambassador, two Camrys, a Fortuner, an Innova, a Maruti Ciaz and a Scorpio.
Shatrughan Sinha took out a roadshow in the state capital which saw the participation of hundreds of residents and supporters.
Sinha popularly known as 'Bihari Babu' had trounced famous Bhojpuri actor Kunal, fielded by Congress from the seat, in the last Parliamentary election.
Gandhinagar has been allotted to party chief Amit Shah, who will make his debut into Lok Sabha elections this time.
The sitting Patna Sahib lawmaker has been at loggerheads with the current BJP leadership since the 2015 Bihar election, over several issues.
Avtar Singh Hit had compared Bihar Chief Minister Nitish Kumar with the Sikh gurus during the occasion of 352nd birth anniversary of tenth Sikh Guru Gobind Singh.