In which of the following Schedules, the names of the states and union territories, and their territorial extent are mentioned?

The names of the states and union territories, and their territorial extent are mentioned in the First Schedule.

Being a sovereign state, India can acquire foreign territories according to the modes recognized by international law, i.e., cession (following treaty, purchase, gift, lease or plebiscite), occupation (hitherto unoccupied by a recognized ruler), conquest or subjugation. For example, India acquired several foreign territories, such as Dadra and Nagar Haveli; Goa, Daman and Diu; Puducherry; and Sikkim since the commencement of the Constitution.