Place the chicken pieces, onion, garlic, ginger, tomato sauce, yogurt, garam masala, cumin, turmeric, paprika, salt, and pepper in the slow cooker. Stir until the chicken is coated evenly.
Cover and cook on low for 6 hours or on high for 3 hours, until the chicken is tender and the sauce has thickened slightly.
About 20 minutes before serving, bring the chicken broth to a boil in a saucepan. Add the basmati rice, reduce the heat to low, cover, and simmer for 15 minutes until the rice is tender and the liquid is absorbed.
Fluff the rice with a fork. Spoon the chicken and sauce over the rice and top with the chopped cilantro.