How to read 均 which stands for "level"?
均

I just can't find this kanji on the dictionary... but I know its meaning which is "level", if I am not
wrong...!

and how to read this for indicating the levels?
for example:

1均
2均
3均

A1均
B2均 ...

Thanks!

Question

How to read 均 which stands for "level"?
均

I just can't find this kanji on the dictionary... but I know its meaning which is "level", if I am not  
wrong...!

and how to read this for indicating the levels?
for example:

1均
2均
3均

A1均
B2均 ...

Thanks!

Answer

As a Japanese native speaker, I've never seen all the words you wrote. 
In general, 均 isn't used alone. 
You probably saw 100均. It's a short form for 100円均一. Like this, 均 usually accompanies other letters, ex. 均等、平均.