I am confused between the forking that can be created because of the 51% attack and the soft fork and hard fork.
Does forks because of 51% attack can also lead to new crypto currency creation?
Any forking that results from a 51% attack is a fork of the blockchain. It is a fork in the data, not in the rules.
The phrases "hard fork" and "soft fork" usually refer to a fork in the Bitcoin rules. So that is a fork due to software changes that implement either a change in the so-called consensus rules or a change in the network protocol.
So they are different in that way.
So far as I know, there has never been a successful 51% attack in Bitcoin, so I don't think we can say for certain what a long term outcome might look like. I guess that all blockchain forks are eventually resolved one way or another.