6013 is a good all purpose, general repair electrode, but since you didn't mention the material grade, you might want to consider whether the 60,000 psi tensile strength of 6013 at least equals that of your base material. If you're under contract, you might want to check the specifications to see whether 60 series electrodes are permitted. In my line of work, I've never seen anything less than 70 series permitted. Depending on material thickness and grade, you might want to preheat before welding. Low hydrogen electrodes may also be required depending on the material grade.