Prepare grill. If using a charcoal grill, place charcoals towards one side of grill and make an indirect area on opposite side.
Coat flesh side of salmon fillet with mayonnaise, then season with Tajin Mexican Seasoning.
Place salmon fillet skin side down on grill over indirect heat. Close grill cover and cook between 5-10 minutes. Salmon fillets vary in thickness and will require different cooking times. Check your salmon after a few minutes. When salmon turns just barely opaque, it is done. Remove to a serving platter and top with Mexican Corn (see below).
Mexican Corn Topping
Heat corn kernels over medium heat for a few minutes until just warm.
Combine corn with mayonnaise, cilantro, Tajin Mexican Seasoning and lime juice.
Place corn mixture evenly over salmon fillet and crumble Cotija cheese over the top.