ANYONE KNOW IF THERE IS AN ADDON THAT TELLS U THE DIFFERENT LVLS THAT U CAN ENTER BATTLEGROUNDS OR WHERE TO FIND THAT OUT AT

Please, refrain from using capital letters everywhere.
Thanks.

Um.... this should be a well known fact already. 10-19 WSG, 20-29 WSG+AB, 30-39 WSG+AB, 40-49 WSG+AB, 50-59 WSG+AB+AV, 60-69 all, 70 all

Hah! "... this should be a well known fact already..."
It seems like you don't even knw it yourself! Let me correct you! :)

First lvl of AV is 51, not 50.
Higher lvl of AV is lvl 61-70, not 70 only!

Rest is correct!