Step 1: Meaning of hotspots
A biodiversity hotspot is a region with very high levels of species richness and a high degree of endemism. Endemic means found only in that region and nowhere else. These regions are priority areas for conservation.
Step 2: Two criteria
The two criteria used for determining a hotspot are: (i) very high species richness, and (ii) a high degree of endemism.
Step 3: Hotspots of India
India has parts of three hotspots: the Western Ghats, the Eastern Himalayas and Indo-Burma. Any two of these can be named.
Final Answer:
A hotspot is a region of very high species richness and high endemism. Criteria: high species richness and high degree of endemism. Two Indian hotspots: Western Ghats and Eastern Himalayas (Indo-Burma is the third).