Is there options?
If not then here or some achievements: (I'm doing an essay on this. lol)
Their theory of the creation of the universe, the theory that the earth goes around the sun, they had the earliest and only known modern language, they.
Also, there is geometry,
Speed of light,
Medicine ( surgery was performed even before 100 BC by Sushruta, Charaka.),
Trigonometry
Definition of sleep and themental condition during sleep etc.etc.
If we are to speak about Ancient India's achievements, then that would extend very much greater than that of the modern science.