Season chicken pieces with salt, turmeric, chili powder, cumin, coriander, garlic, ginger, garam masala, lemon juice, a little yogurt, and oil. Mix well and marinate for at least an hour. Place the chicken in the airfryer at 375°F (190°C) for about 20 minutes, flipping halfway, then increase to 400°F (200°C) for a few minutes to make it crispy. Serve hot with ketchup.