Short answers, pulled from the story.
The earliest Indian art originated during prehistoric settlements of the 3rd millennium BCE, including the rock shelters of Bhimbetka, which contain some of the world's oldest known cave paintings. The earliest paintings at Bhimbetka are around 10,000 years old, often made with a red wash of geru, a powdered iron oxide, and depict human life, animals, and hunts.
Indian funeral and philosophic traditions exclude grave goods, the buried objects that became the main source of ancient art in other cultures. Wood and other perishable organic materials rarely survive the Indian climate, so stone and metal sculpture, mostly religious, makes up most of the best surviving remains.
The depiction of the Buddha in human form first appeared in the Greco-Buddhist art of Gandhara, in what is now southern Afghanistan and northern Pakistan, where Greek and Persian influence met Indian iconography. Before this, the Buddha was represented only through symbols, and the human depiction flourished under the Kushan Empire as Mahayana Buddhism grew.
Indian art was shaped by Hinduism, Buddhism, Jainism, Sikhism and Islam. Generally the prevailing artistic style at any time and place was shared by the major religious groups, with probably the same artists working for different faiths and adapting the iconography to the religion commissioning the work.
The Bombay Progressive Artists' Group was founded in 1952 by six artists, K. H. Ara, S. K. Bakre, H. A. Gade, M.F. Husain, S.H. Raza and Francis Newton Souza, to express India in the post-colonial era after independence in 1947. Though dissolved in 1956, it was profoundly influential in changing the idiom of Indian art.
The Bengal School of Art was an art movement and style of Indian painting that originated in Bengal, primarily Kolkata and Shantiniketan, and flourished during the British Raj in the early 20th century. It was associated with Indian nationalism and led by Abanindranath Tagore, who lived from 1871 to 1951 and has been called the father of Modern Indian art.