Question

Although Buddhism began in India, its highest percentage of followers today can be found in the country of what

Answer 1

The question is a bit tricky, as different sources provide different answers. The percentages can only be estimates, as exact census is always hard to do, and can change with time. It's definitely Thailand or Cambodia, as both have above 90 % of Buddhists. More sourced point towards Thailand though, so this will be the final answer. 

Answer 2

I believe most hindus live in India,
but there's also many in Nepal and Bangladesh?

Sry if I wrote something wrong, i'm from Europe, not the u.s