boca;583269 I read that he had a pen-pal sort of relationship with the Sankaracharya of Sringeri Math. If I was a ruler that believed in the supremacy of my religion and I also happen to be a barbarian (more cruel than ISIS, as you put), I would probably take out the leaders of the religion that I consider as non-belivers [sic!], not send them idol of linga for them to worship. Have you read of this relationship? If so, do you have further details to share?
Tipu had stolen a kingdom where less than 5% were Muslims. He had to survive. So Srirangapattana and Sringeri "datti" (grants) were continued. They were always there.
Moreover, Tipu was a bit superstitious too. So when in trouble, he trusted what he was adviced, even if it did not align fully with his Jihadi tendencies.
All one has to do is to read what was written on his sword to understand his ISIS mentality. He was a hard core Jihadi who wrecked havoc in Kodagu and Northern Kerala, that were not a part of his kingdom.