True, rape is probably much under-reported in India, particularly in the case of that which happens within families, clans and villages. What they actually report seems absurdly low. But thats the case of reporting in most parts of the world.
On the other hand, its still also true that there is no data to compare these rates either way. And there is also the problem of population size. There is no such reliable report that I know of to use for comparison.
The US could easily have a higher rate of rape than India. There is no way to tell.
There are a great many problems comparing crime data between any two jurisdictions — international comparisons being the most problematic.
The “International Association of Chiefs of Police” developed “Uniform Crime Reporting” (UCR) to improve international comparisons. There’s a lot of info on the Internet. You could start here: http://www.nationalatlas.gov/articles/people/a_crimereport.html
Note the definitions used (there are more extensive lists on other sites).