Is NOC from other heirs is mandatory at the time of probating the WILL

My father-in-law have 4 children. 3 boys and 1 girl. My spouse is 4th child for him. She was take care or her parents since 18 years. Her parents were deceased in last year due to health issue. My father-in-law have a self earned property and he wrote WILL in my spouse name and it was not registered due to some his health conditions. One of witness is her brother and signed in the WILL.. My question is, I'm going to probate the WILL in madras high court to transfer the property to my spouse name. Presently property in the name of my father-in-law. What will be the procedure for probate the WILL? How much charge applicable for probate? Is NOC rom her brothers (heirs) is mandatory at the time of probate the WILL? if her brothers won't give NOC or object thr WILL then what will happen? Kindly advice