This example displays a choropleth map of Indian states, with each state’s color encoding its area value through a sequential rainbow scale. The map is rendered as SVG using React and D3. The code loads TopoJSON data for Indian states, converts it to GeoJSON with `topojson.feature`, and projects it with `geoMercator` and `d3.geoPath`. A `d3.scaleSequential` with `d3.interpolateRainbow` assigns colors based on the `AREA_` property, while the legend is prepared but not rendered.