Is it wrong or being a snitch for telling your mom you found a can of beer that was drunken in your ELEVEN year old brothers room?

Definitely not wrong but it may have a bigger impact on him if you told him that it is wrong at his age and that you expect better of him

The only way she can help him is if she knows there is a problem.

The people that came up with the term "snitch" were the ones committing crimes.
Their word means shit.

You already know it's wrong or you wouldn't have posted the question.
You have 2 options, tell your mom, or beat his ass until he gets the point that a beer is not worth an ass kicking.

11 is too young

No thats not wrong. I guess your brother will have a differentview on it (today) but your parents need to know that.

This was the correct action to take - chain of command - the mother must know.

You might want to make sure there's no goblin in there doing all the drinking.

No. If your mom handles it correctly, You might have just saved his life.