Can you eat the seeds of Tamarind if you roast them or boil them?
They're certainly edible, but you might have to work for it.

A Western view from Purdue CropINDEX:


  Tamarind seeds have been used in a limited way as emergency food. They are roasted, soaked to remove the seedcoat, then boiled or fried, or ground to a flour or starch. Roasted seeds are ground and used as a substitute for, or adulterant of, coffee.


People from more native cultures are perhaps more willing to put in the effort:


  ... But I was surprised to find those semi-charred seeds tasting wonderful. They were a little like well-roasted peanuts without their disadvantages, and gave me both the challenge and company I seek of suparis!


I also found a few other mentions of them being a snack food, something people had eaten at home, like this one, which also mentions roasting and de-shelling in bulk with a grinding stone.



As for how to prepare them, I think your best bet might be to roast them, peel with the aid of a mortar and pestle (to crack them open), then soak for overnight or for a day in buttermilk like this recipe suggests. It's worth looking at the full recipe - there's more detail and a little background.

You can certainly try them before soaking as well, if you're looking for something that takes work to eat - you might have to suck and chew a while. As the recipe SAJ14SAJ found says, and says "This is the real test for teeth as it is very hard and crunchy."