In a large pot, melt the butter over medium heat. Add onion; cook and stir for 2 minutes until the onion begins to soften, then stir in the rice. Continue cooking and stirring until the rice is glossy from the butter, and the onion begins to brown on the edges, about 5 minutes more. Add the minced garlic.
Pour in the white wine; cook, stirring constantly, until it has evaporated. Stir in broth 1/3 cup at a time, until the chicken stock has been absorbed by the rice, which will take a few minutes per addition. It'll take about 15-20 minutes to add all of the broth.
Finish by stirring in the Parmesan cheese, tomatoes and crab meat. Spread the risotto onto a large sheet pan to cool for several minutes.
Preheat an airfryer to 400°F.
In a medium bowl, stir together the bread crumbs and the olive oil.
In a small bowl, gently beat the eggs. Form the risotto into balls, using 2 tablespoons for each one.
Dip the risotto balls into the beaten eggs, then coat in the panko mixture.
Working in batches, place the arancini in the airfryer in a single layer and cook until golden brown and crispy, about 10 minutes. Transfer to a plate and serve with marinara sauce.