Which Amendment Act was passed during the Emergency?

NCERT (2025-26): “Consequences … The Parliament also brought in many new changes to the Constitution. In the background of the ruling of the Allahabad High Court in the Indira Gandhi case, an amendment was made declaring that elections of Prime Minister, President and Vice-President could not be challenged in the Court. The forty-second amendment was also passed during the Emergency. You have already studied that this amendment consisted of a series of changes in many parts of the Constitution. Among the various changes made by this amendment, one was that the duration of the legislatures in the country was extended from five to six years.”