This kind of subquery can be converted to a join, so that's how I'd do it here:

Version in SQL:

SELECT t1.col1, t1.col2, t1.col3, ...
FROM table1 t1
INNER JOIN table2 t2
    ON t1.col1 = t2.col1
WHERE t2.col2 = 'xyz'

Version of Linq:

var query =
    from t1 in context.Table1
    where t1.AssociationToTable2.Col2 == "xyz"
    select new { t1.Col1, t1.Col2, ... };

Where AssociationToTable2 is the relationship property; it immediately joins. Alternatively, if you are single:

var query =
    from t1 in context.Table1
    join t2 in context.Table2
        on t1.Col1 equals t2.Col1
    where t2.Col2 == "xyz"
    select new { t1.Col1, t1.Col2, ... };

You may modify them in accordance withNOT IN even while I wouldn't advise using itNOT IN If you can prevent it, performance will suffer, and it nearly always indicates a design fault.

I advise you to review the solutions in this inquiry, If you have to do things the "IN" way, do it..