The biography of Adam von Trott A Good German by Giles MacDonogh has a chapter on Bose and his involvement with nazi Germany in the 1930s and 1940s.
Trott headed up the India Department within Germany's wartime Foreign Ministry and looked after Bose's 18-month stay in Germany during the war.
Bose had visited Germany in 1933 but Hitler refused to see him. Those senior nazis who would see him and wanted to cooperate (an arms shipment to Indian revolutionaries was promised) tended to be on the left wing of the party which was of course wiped out a year later in the Night of the Long Knives.
Hitler approved of British rule in India and said so in Mein Kampf "I would rather see India under British domination than under that of any other nation". And he scoffed at the idea of an Indian uprising. Before the war he suggested to Lord Halifax that the British have Bose shot.
Bose returned to Germany in April 1941. He pressed the Germans to sponsor an Indian government-in-exile and to help him recruit an Indian Army from prisoners taken in North Africa, but initially got only evasive answers. However Trott was allowed to make "generous amounts of money" available to Bose and his cronies. Bose set himself up in a palatial villa near Berlin. He was also allowed to set up a "Free India Centre" in the German capital. Towards the end of 1941 the Germans at last began to build up the "Indian Legion" that Bose had asked for 6 months earlier. The legion numbered a few thousand men but was dismissed by one of Trott's colleagues as "a piece of comic opera which no one took seriously".
But Bose never hit it off with senior nazis. His meetings with Ribbentrop were frosty. His one meeting with Hitler (May 1942) was "anything but cordial". Bose believed the meeting had been a failure and left for Japan towards the end of 1942.