Is animation a engineering or a BE course? Is it a 3 year degree? Should I take any entrance exam to get into animation?

Its not a BE course , but yes you can do graduation ( Bsc ) on animation , normally in maximum of the cases an entrance exam is not needed , but in certain cases it is needed. Normally i suggest to continue a graduation ( distance course- Must be UGC approved ) & take a long term regular course on a

There are various institute and college offering animation in various domains like there are BA, BSC and BFA courses. As such there are no entrance exam but it depends on the college and the institute.