Mother died without will want to transfer property in sister's name

Due to sudden death of my mother there is no will made and we are 03 siblings and the property is on my mother name now me and my brother want to transfer on my sister name the house or in future we need to sell the property, property tax is paid by builder we only give monthly maintenance as well no society is still form so please advise we sibling our ready to transfer on my sister name or else will there be problem to sell the flat because my mother last wish to sell the flat and to buy new, please advise what is to be done in this case ration card we dont have