Don't go by the numbers. Less than 5% of Indian population have ever heard about cryptocurrency and those living in the smaller cities and rural areas are completely unaware of it. There are less than 10 million users in local cryptocurrency exchanges. If you add the P2P users as well, then the figure may come to 20-25 million. But still there is a good chance that there are more users in Nigeria (at least in terms of number of active users).
The daily trading volume of wazirx alone is $229 million and there are other exchanges and i not sure about the P2P volume but i think it is the over all volume and i wont be surprised if the daily volume crosses a billion dollar in the near future combined.
I seriously do not care if Nigeria over takes India or any other country for that matter and i do not see it as a competition, people tend to use P2P if they think that they cannot trust the government and we know the situation in India is not that promising as we hear different stories every day on what the regulation would be.