I already made my personal opinion clear earlier in this thread, about fringe groups. They all have a right to exist, as long as they don't carry out real crimes. Denouncing Hinduism or denouncing Christianity or Islam or any other religion should not be a crime, we do not have blasphemy laws, and should not have the concept at all. No idea is above criticism or denouncement, religious or otherwise. But beating up people is a crime.
Forceful conversions by churches (which @
joekrish brought up earlier) is also a crime. These are crimes because there are victims, real flesh and blood victims. Victimless crimes are not crimes.
Yes, people of all religions should be treated the same, as you say. If it was a Christian group that attacked hindus, or muslims, or anybody else, they should be arrested. In this case it was the bajrang dal people who did it, which is why my ire was directed toward them. Everybody is equal in the eyes if the (Indian) law, especially for violent crimes, no matter which religion they belong to.