There are two syntax errors in your code, and there are also some other issues which do not match Lisp style. Please refer to the corrected code below.
(defun sumFunction(current sum)
(if (/= current 200)
(if (or (eq (mod current 6) 0) (eq (mod current 7) 0))
(sumFunction (+ current 1) (+ current sum))
(sumFunction (+ current 1) sum))
sum))
Here is the result.
(sumFunction 20 0)
;=> 5731