Almost every part of this tree can be used; the leaves and flowers are used in several dishes. The fruit, of course is the most commonly used part - eaten raw, pounded into a pulp with sugar added to it, stored in earthen pots and brought out a little at a time to add heft to the stock for sambar or rasam - a few years ago, small globules of these, sweetened with sugar, almost became a competitive advantage for one of the airlines, forcing everyone else in the skies to serve the same sweets.
For all that, this is not a native Indian tree. It came to India from Africa, but that move happened a very long time ago. Even the name - which has its roots in the Arabic phrase for 'date of Hind'- has a double dose of India in it. With a name like Tamarindus indica, it would be pointless trying to prove its foreign origins!