China seems much more likely. Their government is far more competent and their institutions are far more solid. India has a lot going for it, english creating a natural alliance with the west is a huge one, but they've got a lot to improve before they can move past china. The demographics in china are an issue, but they'll still have around a billion people and the one child policy reversal is helping fix the issue.
India has a large and young population most of whom will have no prospects. That's a recipe for disaster. India is now trending towards the NIGHTMARE scenario PRC family planning / one child policy was trying to avoid. India has the bodies but not the system to develop and harness/coordinate talent enmass. Even PRC with more competent system couldn't wrangle 1.4B+ people. 100s of millions were left behind. Realistically India is going to have a few 100m being uplifted and 1B+ stuck in informal economy / susbsistent agriculture.