I was in India many years ago- and In Mumbai noticed all the houses had a swastika on top of them (except they were reversed). I asked what that was all about, and they said it was a symbol of blessing and prosperity in Hinduism.
I later learned that it’s a sacred symbol in not just Hinduism, but all the whole family of Indo-Aryan religions- including Zoroastrianism, which was the religion of the ancient Persian empire. Today, Zoroastrianism exists in large numbers only in India.
So what’s the connection to the Third Reich? It turns out Hitler really wanted to give his movement a mysterious, mystical, esoteric flavor. That was part its attraction to many young men: it made them feel like they were joining this ancient secret mysterious esoteric movement - something much bigger than themselves- something many young men are attracted to.
So why pick the Swastika? He had always talked about how Germans were the origin of all civilization and cultural advancements in history- that was the Nazi propaganda. But it was hard to point to any ancient grand civilization starting in Germany. They were descendants of a bunch of Vikings, famous mostly for their ruthless killing and looting. So he created this myth that the Germans were descendants of the “Aryans”- the tribe which had created the grand civilizations of Persian empire in the Middle East and brought Hinduism to India.
Archeological and historical evidence shows these “Aryan” tribes probably originated somewhere in what’s now the central Asian steppes-modern day Kazakhstan- and migrated south due to increasingly colder climates, overgrazing of their cattle, and invasions from proto-Turkic nomads in the area.
The word “Iran” actually comes from the word “Aryan”- they were the only ancient civilization which explicitly identified themselves as Aryan. The word Aryan means “noble ones”.
By there is no evidence these tribes ever went to Europe (maybe a few went to Greece). But since that link to grand old civilizations was part of Nazi propaganda, Hitler adapted this ancient Indo-Aryan symbol of the Swastika, and created the story that the Germans were the only pure remaining branch of this ancient tribe.
It was all made-up propaganda.