Bihar Reorganisation Act, 2000
The Bihar Reorganisation Act, 2000 was a law passed by the parliament of India in 2000. Loksabha and Rajya sabha passed the bill on 2 and 11 August respectively and on 15 November 2000, which enabled creation of Jharkhand State out of Bihar.
Source: Wikipedia — Bihar Reorganisation Act, 2000 (CC BY-SA 4.0)