| Name of the Candidate | Party Name | Result |
| AMIT KUMAR | Indian National Congress | 79217 |
| MOTI LAL PRASAD | Bharatiya Janata Party | 56361 |
| ATUL BIHARI MISHRA | Communist Party of India | 4262 |
| BRAJ MOHAN KUMAR | Independent | 3358 |
| PRIYATAM PASWAN | Independent | 2743 |
| UMESH SAH | Bahujan Samaj Party | 2635 |
| SADA BABU SINGH | Independent | 2613 |
| RAMBABU SAH | Nationalist Congress Party | 1488 |
| DEVDHARI NISHAD | Independent | 1305 |
| THAKUR CHANDAN KUMAR SINGH | Independent | 1240 |
| RANDHIR KUMAR | Independent | 1009 |
| TAJUDDIN HAIDAR KHAN | Samajwadi Party | 974 |
| MD. ABBAS SEKH | Independent | 796 |
| RAM NARESH SAH | Garib Janta Dal (Secular) | 636 |
| RAJAN KUMAR | Rajnaitik Vikalp Party | 570 |
| GONAUR DAS | Loktantrik Sarvjan Samaj Party | 555 |
| RAM VILAS BAITHA | Proutist Bloc, India | 500 |
| PREM RANJAN KUMAR SINGH | Bhartiya Jan Hitkari Party | 401 |
| None of the Above | None of the Above | 1105 |
| AC No | Category | Poll Phases | Last Date of Nominations | Date of Polls | Result |
| 23 | GEN | Phase IV | Oct 7th 2015 | Nov 1st 2015 | Nov 8th 2015 |
Riga assembly segment is in Sitamarhi district and is a part of Sheohar Lok Sabha constituency. Riga covers Suppi, Bairgania and Riga community development blocks. Riga is home to 2,67,543 eligible voters of whom 1,42,246 are men and 1,25,281 are women.
Riga, which came into being before the last general assembly elections in Bihar in 2010, is currently held by Motilal Prasad of the BJP who had won the seat in 2010 by defeating his nearest rival Amit Kumar of the Congress by an impressive margin of 22327 votes. While Motilal Prasad received 48633 votes, the Congress nominee secured 26306 votes and was followed by Nagina Devi of the Lok Janashakti Party (LJP) with 18562 votes. Nagina Devi had been elected from the Bathnaha assembly seat which was made a reserved constituency before the last assembly elections.
Ram Sakal Sahani, who had contested the Riga seat on the ticket of Bahujan Samaj Party (BSP), came fourth with 7937 votes.
In 2010, the Congress had won only four seats in 2010 assembly polls to Bihar. The Janata Dal (United) did not nominate any candidate because it went to the polls in alliance with the BJP in the last assembly polls in Bihar. While the BJP managed to claim 91 seats, the JD (U) candidates emerged victorious from 115 constituencies. The Rashtirya Janata Dal (RJD), which contested the elections together with the LJP, put up a dismal performance with only 22 seats.
However, equations have changed now. As things stand today, the BJP and the JD (U) have parted ways and the Lok Janashakti Party (LJP) is now a part of the BJP led National democratic Alliance (NDA) which is ruling the centre. On the other hand, the JD (U), the RJD and the Congress have come together.
One of the eight assembly segments located in the Samastipur district of Bihar, Riga is one of the six assembly constituencies that combine to form the parliamentary constituency of Sheohar which is currently represented by Rama Devi of the BJP who retained the seat by defeating former Sheohar MP and RJD candidate Mohammad Anwarul Haque in the 2014 Lok Sabha elections
Other five assembly constituencies are .Madhuban, Chiraia, Dhaka, Sheohar, and Belsand.
BJP has fielded its sitting MLA Motilal Prasad to take on Amit Kumar Tunna of Congress in Riga. Riga is home to one of the largest electorates in the state with a total of 2,67,543 eligible voters. BJP's Motilal Prasad is the sitting MLA of the constituency. In the first ever elections held in the constituency in 2010, Motilal Prasad defeated Amit Kumar of Congress with a big margin of 22,327 votes.
Prasad won 48,633 votes as compared to 26,306 votes of Amit Kumar. Both the candidates had a similar face-off in the last Assembly election in 2010. Hence, they know the strengths and weaknesses of each other. But this time Prasad is riding a wave crest with surging popularity of PM Modi at the Centre with focus on development issues.