But you guys are loudly proclaiming that your current culture "inherits" from IVC, which means you converted to accept various parts of IVC.
So, which one is it? Is your culture completely indigenous, or did it accept outside influences from the IVC?
Or, if you are going to claim that IVC was indigenous, then how do you make that claim? The IVC was not conquered by anyone else during their heydey -- they were a distinct civilization and political entity. In later years, the region was conquered by various invaders (some from north/central India) but, as we noted, the conquest was only political. The cultural influence was strictly in reverse -- from IVC to central India.
So, everyone other than NW Indians are converts to a foreign belief system.