Mutation on Will base be registered directly or one has to take probate or go to civil court?

Hello sir, We have a family dispute. Below are the summary, please guide. My aunty(bua) died in 2019 and made will registered in 2014. She was not married and stayed with us. She allocate all the property(1 and 2) in will to my father and my sister. City survey rejected our mutation right without giving any reason. We appeal in prant and judgement came in our favour that as it is registered will entry must be done and opponent has to go to civil court if they have any dispute. Now they have appealed in collecter and they are arguing that we have to first go to civil court to crystal clear our right and then come for mutation. They are also asking for the genuineness of will. But it is registered in mamlatdar court. They also have an argument as we are Muslim muslim personal law will be applicable. My questions are: 1) Does prant or collector or special officer has authority to check the genuineness of will and based on that they give the judgement? 2) As it is registered will can't theyutate the entry and ask the opponent to go to court if there is any issue? 3) If muslim law is applicable, can collector give judgement based on that? My father I also a lawyer and he says that for muslim law, genuineness of will, dispute opposition has to go to court not us as prant, collector does not have the authority. And collector must have to mutate the entry as it I registered will. Please guide.