Alright kiddo, so you know how some people do bad things because they believe in something very strongly? That's kind of what's happening with Hindu terrorism.
Some people in India who follow the Hindu religion believe that Hindus are superior to people of other religions, and they want to protect Hinduism at any cost. This sometimes leads them to do bad things, like bombing places or hurting people who don't follow Hinduism.
This is really not okay, because hurting people is never the right thing to do, no matter what religion you follow. It's important for people of all religions to respect each other and coexist peacefully.