I took the liberty of copy and pasting this for you from another commenter.

Violent crimes against women is a major problem in India.

People who try to compare rape statistics are missing the point because sexual assault legislation differs widely between countries and the way rape is counted differs too (take Sweden for example).

The reasons for not reporting rape are quite involved in a country like India, and is tied to how it is often a very oppressively patriarchal society. First off, I'm not talking about India's rich affluent upper class that lives in cities, but the vast poor majority:

Marital rape is not seen as a crime of rape, but as a domestic abuse case. Martial rape simply isn't taken seriously, and is rarely reported or prosecuted.

Women are still extremely dependent on men in Indian society. If a woman is not "attached", she is seen as "available" - this eventually leads to problems, like rape. So it is always in the interest of families to "marry their daughter off". The dowry system is still rampant, and a girl child is often seen as a burden. In India almost everybody is married through the "arranged marriage" system, a marriage market essentially. If a woman has sex before marriage, she is seen as being spoiled. Virginity is still seen as a requirement by many indian families.

To extend the above if an unmarried woman is a rape victim, her chances in the arranged marriage market are ruined. Her dowry will increase exponentially. This is something that will force women and families not to report rape. M olestation is something that some of Indian women have to deal with growing up. Unfortunately if it's someone from within the family, it is usually hushed up. Not just for the above reasons, but for the fact that the family honor must be preserved. Indian society is very hierarchal, and if an "elder" is the perpetrator, there is a natural tendency for the whole thing to be hushed up.

If there is an inter-caste rape, where the perpetrator is from a higher caste, the case might get hushed up, because the higher caste community in villages often controls what cases the police end up filing.

If there is an inter-class rape, where the perp is from a higher class, it is possible to buy the police, since they are unfortunately often quite corrupt.

If politics is involved, especially political party workers - the case gets hushed up too. Low level politicians and their workers in rural and suburban india are often basically opportunistic thugs and criminals.

If a sex worker is involved in rape, it will never get reported - since in India sex workers have no rights and are generally considered subhuman by society.

If a woman is proven to have an existing sexual relation with the perp, the case will be laughed out of the police station, just like marital rape. "Character" judgement happens to an absolutely ridiculous degree in India. Many women just avoid reporting rape unless it is particularly brutal and involves violent injuries, since the embarrassment is seen as not worth it, along with the social outcasting that will inevitably follow.

Tldr : India has a very long way to go when it comes to womens rights, comparing statistics is futile and there are multiple india-specifc reasons why rapes don't get reported.