The first paragraph clues the reader in to the fact that the story is not happening in the United States. The main hint in that paragraph for me is the fact that the children had "tea." Tea is not an American thing to have. Sure, my grandma likes tea, but sitting down for afternoon tea is not a typical American thing.
The next clue for me is the first line of dialogue.
"Please, ma, please,'' they begged. "We’ll play in the veranda and porch—we won’t go a step out of the porch.''
"Veranda" and "porch" are not typical American words either. Kids might play on the patio or the deck, but not the veranda/porch.
The final big clues to the reader are the names of the kids. Raghu, Manu, and Ravi are not typical American names. Those names suggest southeast Asia. The narrative being in English and characters having tea then suggests an English speaking Asian country. My best guess is India, since at one point it was part of the British empire.