Over the last 100 million years, the plate have moved 2,100 kilometers. how many centimeters per year dose it move eastward

20 centimetres (7.9 in) per year

Explanation:

In the late Cretaceous, approximately 100 million years ago and subsequent to the splitting off from Gondwana of conjoined Madagascar and India, the Indian Plate split from Madagascar. It began moving north, at about 20 centimetres (7.9 in) per year,[9] and is believed to have begun colliding with Asia as early as 55 million years ago