what were the earliest experiments of Indians in rocket technology ?

Amazingly, Indians were experimenting with rocket technology even in ancient times. The Chinese were the first in this field, and because of extensive trade between India and china in those days, their ideas spread to India too. Rockets were used to military purposes by both Hyder Ail and Tipu sultan, the rulers of Mysore. These rockets were successfully used in the Anglo-Mysore wars. These rockets were so impressive, that the British decided to develop their own rockets.

In fact, several Mysore rockets were sent to England, and they inspired William Congreve to invent the Congreve rocket in 1806. The Congreve rocket is considered to be the predecessor of modern artillery rockets.