The Nazis didn't do anything in the Indian subcontinent!
It was ruled by the British, or allied that way so the Nazis couldn't do anything there even if they wanted!
The Nazis sent many expeditions to Western China, not because they expected to find Aryans there, but because they believed Western China (then Tibet), could be an ally of theirs when they achieved world domination. They could justify this to the Germans by saying the Tibetans were their allies because they are descended from a pre mongoloian stock of Aryan people. In actual fact, the Nazis were right on this, as recent discoveries have shown.
But they did this so they could have allies in the Far East. They chose Iran as their Middle Eastern ally, and this too was made justifiable by convincing them of an Aryan connection when in fact no such connection existed.
The Nazis didn't step foot in British India though. There was a very solid policy of keeping track of foreign spies in British India.
You appear to be trying to tie the marrying cousins thing to the Nazis
Tell me you're jokiing, right? The concept of marrying cousins, not only occurred in the subcontinent, but also Arabia, Africa, even Europe it was occuring, didn't matter whether they were Aryan or not. To suggest the concept of marrying cousins to form breeding farms is a Nazi concept is ridiculous.
That Himmler carried around the Gita is speculation. Though it might be true - he wasn't particularly bright, and his silly theories have been taking up by modern day neo nazis who really are a bit thick when it comes to this Aryan stuff.
Change this if you can. This is wriiten in 500th Century BC.
By: M. Sâdeq Nazmi-Afshâr
I am Darius, the great king, the king of kings
The king of many countries and many peoples
The king of this expansive land,
The son of Wishtaspa of Achaemenid,
Persian, the son of a Persian,
'Aryan', from the Aryan Race
"From the Darius the Great's Inscription in Naqshe-e-Rostam"