The narrator of Kim is your average all-knowing third-person narrator: it reports on the feelings of the characters, and it seems to know pretty much everything about pretty much everybody. Of course, like everyone else on this book, it's really focused on Kim. But it gives us access to Mahbub Ali and Creighton from time to time, so it is clear that the emphasis on Kim is a choice rather than a necessary limitation on the narrator's perspective.
One thing we do find interesting about this otherwise run-of-the-mill narrator is the distant, detailed perspective that it sometimes assumes. So, to use film terms, there are moments when the narrator's eye zooms out to take in incredible amounts of visual information. Whenever Kim stops to watch the crowds on the train or the Grand Trunk Road, or when he encounters the different cities of India or the landscapes of the Himalayas for the first time, the narrator will give us these spectacular snapshots of the range of people or the beauty of the landscape, drawing attention to the size and diversity in front of Kim.
As a more specific example, here's a passage from Lurgan's house in Simla describing the guests that come in and out every day:
There were small Rajahs, escorts coughing in the veranda, who came to buy curiosities—such as phonographs and mechanical toys. There were ladies in search of necklaces, and men, it seemed to Kim—but his mind may have been vitiated by early training—in search of the ladies; natives from independent and feudatory courts whose ostensible business was the repair of broken necklaces—rivers of light poured upong the table—but whose true end seemed to be to raise money for angry Maharanees or young Rajahs. (9.107)
And the description goes on for almost a page from here. The narrator gives us a sense of the variety of people pouring in and out of Lurgan's house while at the same time suggesting the sheer number of different kinds of people that you can find in India as a whole. Lurgan's house gives a cross-section of Indian society itself, and the narrator piles on detail after detail to emphasize the scale and scope of that society. Everything about India is huge, and these epic descriptions in Kim really draw attention to that fact.