It's complicated. Essentially, "invasion" implies a degree of conquest which is inconsistent with our evidence of the transition between Indus Valley Civilization and the Indo-Aryan civilization. Complicating this is the fact that many modern Indians, especially in the North, consider Indo-Aryans, and by extension "Hinduism", to be autochthonic: that is, that India represents the genesis of Indo-Aryan, and more broadly Indo-European, culture. This is done for a mixture of nationalist and religious reasons that are complicated to get into, but this often goes with the ideas that Vedic Sanskrit is the original Indo-European language and that Hinduism is Vedic Religion, both of which are clearly false.

In any case, lets look at where Indo-Europeans first appeared. Most, though certainly not all, scholars place the origen of Indo-European culture about 7000-5000 BCE around the area now called the Pontic Steppe. The earliest known branch was the Hittite Civilization, as they lack key cognates for technology, such as the words for chariot and axel, then the "Tocharins." The Proto-Indo-Iranians are associated with the last phase of Proto-Indo-European culture located East of the Caspian Sea. The Indo-Aryan/Aryo-Persian split happened some time between 2000-1600 BCE. The Indo-Aryan branch had sustained contact with the BMAC Civilization and potentially some contact with the IVC, and while raiding may have been common, full scale invasion seems to be unlikely, rather population replacement via migration, assimilation, and trade seem more likely. The Indo-Aryans slowly moved into North India, reaching the areas previously dominated by the IVC around 1600 BCE and moving into the Gangetic plain around1400.

The IVC shows signs inconsistent with invasion or warefare in its late stage. Rather we see population decline beginning in the 21st century BCE and continuing at a relatively steady rate until the 14th by which they had migrated and dispersed, some assimilating into Indo-Aryan. Around this period, there was a large scale climate change that made the dense urban population suffer, especially with the hierarchy in the cities causing those in the lower rung to have fewer resources. We find evidence of intercommunal violence rather than the extracommunal we'd expect from warfare. While we do find mass graves, they are often associated with disease rather than violence.

So now, we typically refer to the movement as a Migration rather than invasion. Furthermore, rather than full scale replacement of the native peoples, we are probably looking at long term assimilation that had mutual influence.