Succession

My grandfather had two brothes. He was second. His younger brother married second time after the death of his 1st wife. He had 2 daughters from his 1st wife. His 2nd wife had a son who was my uncle by relation. He didn't marry. His mother died 4 years ago. He has died on 8th October. Being unmarried he is survived by none.One of his step elder sister is also dead.All the property is against his name. He had no relationship with his step-elder sisters. All his property is acquired by us(my 2 brothers and me). I performed all the posthumous rituals after his death. He has not left any will. Now I want to will his alive step sister and the sons and daughters of his dead step-elder sister get his property? Or we will get his property? We have got warison certificate against our name.His death certificate and other documents are with me. Moreover he has an FD and a savings A/c in a bank.The entire money he saved was earned by him as he served in a Samabay bank? Can we withdraw the money from the bank maintaining all formalities? Please help.