In bowl do marination add red chili power,biryani masala, yougrt,ginger garlic paste, turmeric,,lemon juice,oil salt. keep for atleast 5 hr or overnight.
Wash and soak rice for 30 mins, Heat heavy bottom pan or a pressure cooker with oil, add whole spices, onions fry till golden brown, green chilies keep stirring,take out some onion for sprinkl, on low heat add marinated meat, add half coriander,mint make meat soften by coveing or pressure cooker.
While meat is cooking, boil water in big pot. add whole spices and salt ,then add rice and cook untillrice cooked 85% means not too soft. now drain rice and keep saparate same time mutton also gets cooked.
soak soffron in mlik. Its layring time. take out greavy and in same pot add half rice first add little fried onion on it and corinder or mint leavs now add all cooked gravy than again add remaing rice sprinkle all same as befor noe pour saffron in center or some 3 4 area or soad orange food color in water and spreadeit on last of rice.
now cover pot with presure cooker or with lid by using cloth in between to make it cover and heat tawa on high flam and now keep tawa very carefully below pot and cook in low flam fot 12-15 mins.this ia call dum.
after 15 mins aroamtic mutton biryani is ready serve with fine chopped opnion,tomato and lemon salad or corinder-mint -yougrt -salt raita also.