Union Government
(1) Where the same or substantially similar legal questions are pending before the Supreme Court and one or more High Courts, or before two or more High Courts, and the Supreme Court is satisfied these are substantial questions of general importance, it may withdraw the case(s) from the High Court(s) and decide them itself, later returning them to the High Court to be disposed of in line with its judgment on the legal questions. (2) The Supreme Court may also transfer any case, appeal, or proceeding from one High Court to another, if expedient for the ends of justice.
When the same important legal question is being litigated separately in multiple courts around the country, the Supreme Court can pull all those related cases together, decide the shared legal question itself, and then send the individual cases back to their original High Courts to be finally resolved consistently with that ruling - avoiding conflicting decisions on the same legal issue from different High Courts.
This power is often used when a new law faces multiple, near-identical legal challenges in different High Courts across the country - the Supreme Court can consolidate them to give one authoritative ruling instead of having different High Courts potentially reach conflicting conclusions.