How did cross-voting and absenteeism by Opp'n MLAs help NDA win Rajya Sabha polls?

Around eight MLAs from the BJD and three from Congress cross-voted in favour of a BJP-backed candidate, helping him win the Rajya Sabha elections. On the other hand, three Congress MLAs and one RJD MLA remained absent while voting, resulting in the BJP winning all five Rajya Sabha seats from Bihar. The BJP-led NDA won 21 out of 37 seats.