Indian rhinoceros is a natural inhabitant of which of the following states in India?

The correct option is Assam.

The Indian rhinoceros (Rhinoceros unicornis), also known as the greater one-horned rhinoceros, is native to the Indian subcontinent. Historically, its range extended across the entire northern part of the Indian subcontinent, along the Indus, Ganges, and Brahmaputra river basins.

Today, however, the species is primarily restricted to small habitats in the Indo-Gangetic plains and the foothills of the Himalayas. The state of Assam in northeastern India is the primary and most famous natural habitat of the Indian rhinoceros. Kaziranga National Park in Assam holds the largest population of one-horned rhinoceroses in the world, sheltering more than 70% of the global population. Other protected areas in Assam, such as Pobitora Wildlife Sanctuary and Orang National Park, also support significant populations.

In contrast, states like Maharashtra, Tamil Nadu, and Karnataka do not have natural habitats for the Indian rhinoceros; their climates and ecosystems (ranging from the Deccan Plateau to the Western and Eastern Ghats) support different types of megafauna like Indian elephants and Bengal tigers, but not the swampy, alluvial grasslands required by the one-horned rhino.