Is mutation necessary to sell my part of property

Hi, I am resident of sahibabad ghaziabad, my father died 20 years back he had registered will and divided a house between me and my brother, we have not done mutation till now ,now I would like to divide sell my part pls let me know how can we sell our part. I have a sister also but her name is not in the will 1. Is mutation necessary to sell my part 2. Can my brother stop me to sell my part and file case 3. is my sister's NOC required and compulsory 4.advice us steps to sell our part