The issue of illegal immigration into India from Bangladesh has been a politically sensitive one and has sparked demands to fence the porous India-Bangladesh border (IBB). Given its implications for national security, the question of fencing has come up before various judicial forums from time to time, including the Supreme Court and more recently, the Calcutta High Court . Here’s what to know about what the two courts have said on the issue recently and the timeline of the proceedings. In December 2023, a five-judge Supreme Court Constitution Bench was hearing a challenge to the constitutional validity of Section 6A of the Citizenship Act, 1955, which granted citizenship to immigrants who entered Assam before January 1, 1966. The top court had sought to know from the Centre the status of the border fencing and the steps it intended to take to complete it, and the estimated timelines for completion.…