IF(Logical_test) values for multiple

I've been using this in my workbook to show cefor multiple values function.

=IF(E6=B4,C4,IF(E6=B5,C5,IF(E6=B6,C6,IF(E6=B7,!C7,IF(E6=B8,C8,IF(E6=B9,C9, IF(E6=B10,C10,IF(E6=B11,!C11,IF(E6=B12,C12,IF(E6=B13,C13,IF(E6=B14,C14,IF(E6=B15,C15,))))))))))))

Yeah, it's too simple...at least it's working...

Until recently, I faced problem on updating and adding much more values into the table....(the tables going further till B200 and C200)

Need help to make the formula simpler, for infinite loop....

Thanks.