Well, people all over the world eating the foods which grown in India for example spices so if world can eat then why not their own people? The bloody corrupted government is the reason for all the issues not the population rate, China used their human resource to become the most super power in this world right now so India can be the one too if someone who rules the country with some knowledge.
China was able to use their human resources in a better way, because they implemented the one-child policy in 1980, which allowed the government to give proper education and medical care for all of the citizens. And the Chinese economy started to grow at a good pace, around 10 years after the one-child policy was implemented. What China did was not to reduce the population size. If you check the Chinese census, you will find that the population is still growing, although at a reduced pace. But the population growth slowed down and it made sure that more natural resources are available to everyone. And on the other side we have India, which has around one-third of the area as China and almost the same population. Having a huge population is a disadvantage, when that population doesn't have sufficient education or skills.
Huge population is a disadvantage where I agree with that but India is falling not due to the population as far as I know, the wrong ideas and proper political knowledge from the ruling parties lead them to where it is.