Cidco flat transfer process after death

Hi all,

I want to transfer my flat name from my deceased father to mother. 

I live in Kharghar and my building come under cidco. My father already made nomination for flat in which my mother has 50% and me and my brother 25-25%.

I want to know the process and documents required for this. 

Also is there online process available for this ?

And many charges i have to pay