If biryani rice is still uncooked what should've Do

Maybe you cooked it at too high of a temperature, evaporating the water long before the rice actually cooked. Maybe you took the lid off of the pot too early, letting the steam escape. Maybe you didn't add enough liquid to begin with. Whatever the case, if your rice is looking dried out, or the texture is still hard or crunchy when all the liquid has been absorbed, add up to ½ cup water and return to a simmer with the lid on. Be patient. Don't raise the temperature to rush the rice — that'll just put you right back where you started.

When you find the rice is undercooked, do not eat it or throw it away. Here is a simple method to solve the problem: use chopsticks to stick a few holes in the rice center, sprinkle the same amount of water diluted wine into the holes, and then simmer for five minutes.

If your rice are very hard which mean they are under cooked when assembling the Biryani pot, you can add extra water in dum to soften but remember the gravy also has some water.