Whisk the lime juice, soy sauce, and brown sugar in a large baking dish. Add the tofu and marinate, turning occasionally, for 10 minutes.
Heat the oil in a large nonstick skillet over medium heat. Season the tofu with 1/2 teaspoon salt. Cook until browned, 2 to 3 minutes per side.
Divide the mayonnaise, carrots, and pickles among the pieces of baguette. Top with the tofu, cilantro, and Sriracha.