Areas of High Density
These areas have a high density due to fertile land and high amount of precipitation e.g. Kerala, West Bengal and Tamil Nadu.
In these regions, a larger number of people can be provided sustainance per unit of area due to availability of fertile land which can produce more food for a large number of people.
But the situation is entirely different in the case of Union Territories like Delhi, Chandigarh and Pondicherry. These regions are highly urbanised and offer job opportunities in industrial and service sectors.
The areas having fertile soil and those having good employment opportunities are densely populated.
 Areas of Moderate Density
States and Union Territories in which the density of population ranges between 100 and 400 persons per square kilometre are called areas of moderate density of population.
They are Andhra Pradesh, Assam, Dadra & Nagar Haveli, Goa, Gujarat, Karnataka, Madhya Pradesh, Maharashtra, Orisa, Rajasthan, Tripura, Jharkhand, Chhattisgarh, Jammu and Kashmir, Uttarakhand, Himachal Pradesh, Nagaland, Manipur and Meghalaya.
This region includes largest part of the country in terms of area.
Broadly speaking moderate density of population is characterized by the areas in which the agriculture is handicapped by rugged topography, lower amount of precipitation and paucity of water for irrigation.
 Areas of Low Density
All the remaining parts of India having a density of population less than 100 persons per square kilometre may be classified under this category.
The States and Union Territories falling under this category include Arunachal Pradesh, Mizoram, Sikkim and Andaman & Nicobar Islands.
Low density population areas are characterized by rough terrain, low rainfall or unhealthy climate.
Agriculture cannot be developed in too dry or cold areas.
Uneven topography and poor agricultural resources put a limit on urbanisation and industrialisation.
Difficulties exist not only in transport and communication in the hilly and mountainous areas but also in the over all levels of economic development.
That is why the density of population in all these areas is low.