A choropleth map of India supports drill-down navigation by clicking a state to zoom into its district boundaries. Clicking a district returns the view to the national level. The React component uses `d3.geoMercator` and `d3.geoPath` to project TopoJSON features from two remote datasets (state and district boundaries), rendering them as SVG paths with `d3.zoom` and `d3.zoomIdentity` to animate the zoom transition to each clicked feature’s bounding box.