Wash and cut the chicken into small pieces. Marinate in the curds, red chilli powder, salt, ginger garlic paste. Keep it aside for at least two hours.
Wash and soak the rice for 20 mins. In the rice cooker, place the plate and add the drained rice, water, and salt. Press the cooker to the cooking mode. This should be done when the chicken is almost half done.
Chop the onions as julienne and deep fry to get roasted onions. Keep it aside.
Heat a kadai with cooking oil and ghee mixture. Add the green chilies and saute well. Add half of the mint leaves, coriander leaves and saute well.
Next, add the chicken with the marinade and cook till the masala is well absorbed and almost dry. Add the ground spice masala. Mix well.
Add half of the fried onions to the chicken, along with the remaining mint leaves and coriander leaves.
Once the chicken is dry, add to the cooking rice. Mix well add the remaining fried onions (save a little for final garnish). Close the lid again. The rice cooker changes to keep warm automatically when it is cooked.
Since the cooker continues to remain in the "Keep warm" mode, the biryani gets dum cooked.
Notes
Even if you are using regular rice, it's good if you add 1/2 less water than advised. The moisture from the chicken will take care.