A non recursive enumerable language is always countable as it subset of $\sum ^{*}$ which is countable set and subset of any countable set is also countable.
Set of non RE language is uncountable because we can write ,
Set of all language = set of all RE language $\cup$ set of all non RE language
we know set of all language is uncountable .
Set of all RE language is countable .
So, Set of all non RE language has to be uncountable to make set of all language set uncountable.
