Explanation:

A biodiversity hotspot is a biogeographic region with a significant reservoir of biodiversity that is under threat from humans. To qualify as a biodiversity hotspot on Myers 2000 edition of the hotspot-map, a region must meet two strict criteria: 1. it must contain at least 0.5% or 1,500 species of vascular plants as endemics, and 2. it has to have lost at least 70% of its primary vegetation. Regions that satisfy these criteria exist in India and are described below:
Western Ghats are a chain of hills that run along the western edge of peninsular India. Their proximity to the ocean and through orographic effect, they receive high rainfall. These regions have moist deciduous forest and rain forest. The region shows high species diversity as well as high levels of endemism. Much of the world's spices such as black pepper and cardamom have their origins in the Western Ghats. Over 60% of the reptiles and amphibians are completely endemic to the hotspot.
Eastern Himalayas is the region encompassing Bhutan, northeastern India, and southern, central, and eastern Nepal. The region is geologically young and shows high altitudinal variation. The Himalayan mountain system is the world's highest, and home to the world's highest peaks, which include Mount Everest and K2. The Himalayas have profoundly shaped the cultures of South Asia; many Himalayan peaks are sacred in Hinduism, Buddhism and Sikhism.                                                                                                      
Indo-Burma region encompasses several countries. It is spread out from Eastern Bangladesh to Malaysia and includes North-Eastern India south of Brahmaputra river, Myanmar, the southern part of China's Yunnan province, Lao People’s Democratic Republic, Cambodia, Vietnam and Thailand. The Indo-Burma region is spread over 2 million sq. km of tropical Asia.                          
Sundaland is a region in South-East Asia that covers the western part of the Indo-Malayan archipelago. It includes Thailand, Malaysia, Singapore, Brunei and Indonesia. India is represented by the Nicobar islands. The United Nations declared the islands a ''World biosphere reserve'' in 2013. The islands have a rich terrestrial and marine ecosystem that includes mangroves, coral reefs and sea grass beds.