NEW DELHI: The BJP-led NDA is likely to lose a seat in the Rajya Sabha while the Congress-led opposition could improve its tally in the upcoming biennial elections for 26 seats across 12 states.The Election Commission on Friday announced that polling for the Rajya Sabha seats will be held on June 18. The seats are falling vacant due to the retirement of incumbent members between June 21 and July 19, including former prime minister HD Deve Gowda, Congress president Mallikarjun Kharge, senior Congress leader Digvijaya Singh, and Union ministers Ravneet Singh and George Kurian.Elections will be held for four seats each in Andhra Pradesh, Gujarat and Karnataka; three each in Madhya Pradesh and Rajasthan; two in Jharkhand; and one each in Manipur, Meghalaya, Arunachal Pradesh and Mizoram. Bypolls for one seat each in Maharashtra and Tamil Nadu will also be held the same day.Of the 26 seats going to polls, the NDA currently holds 18, the Congress four, the Jharkhand Mukti Morcha (JMM) one and the YSR Congress Party (YSRCP) three.However, based on current assembly numbers, the NDA is expected to secure 17 seats, while the Congress may improve its tally to five seats. The JMM is likely to win two seats, while Tamilaga Vettri Kazhagam (TVK) is projected to bag one seat in Tamil Nadu, according to the PTI report.The NDA currently has 149 MPs in the 244-member Rajya Sabha, while the opposition has 78 members and non-aligned regional parties hold 17 seats.The Election Commission has fixed June 8 as the last date for filing nominations.The bypoll in Tamil Nadu was necessitated after AIADMK leader C Ve Shanmugam resigned following his election to the state assembly. Going by current numbers, Vijay-led TVK is expected to win the seat.In Maharashtra, the bypoll is being held following the resignation of NCP leader Sunetra Pawar after her election to the state assembly. The NDA is expected to retain the seat.In Karnataka, the Congress is projected to win three of the four Rajya Sabha seats, with the BJP likely to secure one. In Madhya Pradesh and Rajasthan, the BJP is expected to win two seats each while the Congress may get one seat in both states.In Andhra Pradesh, the Telugu Desam Party (TDP) is likely to sweep all four seats, while the BJP is expected to win all four seats in Gujarat.In Jharkhand, the JMM-Congress alliance is likely to secure both seats, though the BJP may attempt to win one through cross-voting support.