on 3 and 6 you did not clarify whether it is addition, subtraction, multiplication, or division.
Therefore, I have worked out all possible solutions.
If 2(3 - 6 x 3 - 5) then the solution is 12.
If 2(3 + 6 x 3 - 5) then the solution is -36.
If 2(3 / 6 x 3 - 5) then the solution is -2.
If 2(3 x 6 x 3 - 5) then the solution is -72.