Zero which is an important invention in the history of mathematics.
Decimal system was also discovered in India in Harappa
Pythagoras Theoram was also discovered here.
The Arthashastra of Kautilya mentions the construction of dams and bridges
The origins of the spinning wheel (Charkha) are unclear but India is one of the probable places of its origin
Indigo was used as a dye in India, which was also a major center for its production and processing.
During the Vedic Period (1500-500 BCE), Sanskrit texts such as the Vedas were composed in India.
Trignometery also originated here.
There are many more but I was only able to provide this much
There are many more but I can Only give u this much.