1. If you are diet conscious, you can reduce the coconut milk ratio to 1 cup (i.e for 1 cup of rice, add 1 cup each of water and coconut milk) or entirely omit it and replace it with 2 cups of water. But coconut milk makes big difference in preparing this biriyani.
2. If you are using basmati rice, then the ratio will be different i.e for 1 cup of rice 1 ½ cups of water.
3. If you are using store bought coconut milk add just a couple of spoons. As they are very thick, adding more will overwhelm the taste of dish with coconut taste.
4. Do not add extra water as the chicken itself will release water.