Can I set fire to tree stump?

lol - you could pour some kerosene on it and burn it. Make sure to do it after a rain and keep a hose handy,

I'm no authority on them, but because it is so dense, it is probably going to be difficult to keep it burning, even with the help of kerosene. I believe there are some chemicals that you can pour on it to accelerate it's decay. After being stumped by a few stumps in my yard, I found a guy with a stump-grinding machine that made short-work of them.

Or you could just do it the old fashioned way with a ax and then try pulling it out with a truck.