Is it true Anger is one obvious type of door which leads ATMA to hell .........?

yes, it is true. we are taking some pills for some illness. These pills though cures our illness but makes side effects and then we get treatment for that side effects too. similarly, the anger may be the human nature, but it makes more side effects and that side effects leads to hell is true. That is why our elders say not to get anger, and also if anger comes they say to reduce. you can see many people while they get anger go silent or drink water. This is the reason.