Mayank Agarwal became the 4th Indian Test player whose maiden Test century was a double. Shikhar Dhawan’s 187 is the highest by an Indian on debut, followed by RG Sharma’s 177.
Note the tragic case of Karun Nair. Perhaps he will soon get a chance to redress matters.
Also see this link for all Test players whose maiden century was 200 or more:
http://stats.espncricinfo.com/ci/content/records/230132.html