In 2016, the population of India was 1.324 billion. If the government regulates online gambling and only a very small percentage of the population plays, the government will make a lot of money in taxes.
The Indian government will surely make alot of money through taxes cause India are know for their love for sport, especially cricket and India is a very traditional country which is why I'm surprised that their government law commission endorsed and license gamble site but I hate the fact that they categorized crypto currency with credit card not as legal tender payment.