If The Chinese and Indian governments embrace bitcoin and if there is an adoption rate similar to the US at 0.87% that would be 21 million users alone. A lot of if’s but interesting to think about.
I think that China has one of the fastest growing adoption rates in the world already
there are so many exchanges,exchangers and companies that work with bitcoin,it is inevitable that China becomes
the leader in several years to come,India on the other hand,has always been a fiat country,people there
are increasingly suspicious of banks,atms,online money etc. and that is despite having one of the best computer specialists and programmers in the world
also India's politicians have shown they are not exactly a bright bunch-calling bitcoin a ponzi and a pyramide and trying to make it illegal
so I think China will be an undisputed adoption leader in the years to come,while India's perspective is not that clear