Concept:

• Biodiversity hotspots are regions that harbour plant and animal life that are endemic to them and under threat from humans.
• For a region to qualify as a biodiversity hotspot, it should fulfil the following criteria:
  • At least 1500 vascular plant species should be endemic to the region.
  • The region should have 30% or less of its original vegetation.

There are 4 Biodiversity hotspots in India:

• Himalayas:  It includes the whole Himalayan mountain chain.
• Indo Burma Region: The whole north-eastern part except Assam.
• Sundaland: Nicobar islands group.
• The Western Ghats: Running along the entire west coast of India.

Explanation:

• The Aravalli Range is the oldest Residual fold mountains in India.
• The Khasi Hills is a low mountain formation on the Shillong Plateau in the Meghalaya state of India. 
• The Himalayas is one of the biodiversity hotspots of India.
• The Vindhya Range(also known as Vindhyachal ) is a complex, discontinuous chain of mountain ridges, hill ranges, highlands and plateau escarpments in west-central India.

So, Himalaya is one of four biodiversity hot spots of India.