who all are legal heirs in class II

Hi, The deceased person does not have any children(s) and parents (so no class I heirs). She has nominated her nominee to one of his brother’s child. She has four brothers out of which only one is alive and he also does not have any child (he is class II heir as of now). Now all her deceased brother’s children’s are also claiming as class II legal heir whereas they have never faced her and deceased person also didn’t wanted to share her property among them. It would be very kind if you can answer following queries with appropriate laws, 1. Can all deceased person sibling’s(who all are also died) children’s can claim as legal heir? 2. Can legal heir can only be her alive real brother who is class II heir as of now and other deceased sibling’s children’s can not claim as legal heir 3. Can nominee decide to rent out property? 4. Can nominee donate the property to any trust, if nominee does not have any monetary interest and no one identify their self as legal class II heir in next 1 month? 5. What if nominee does not bear the maintenance of the flat after flat gets transferred on nominee name, who will have the liabilities? How society will tackle this? Thanks for your answers.