Transfer fee for sale deed of flat between blood relative

Hi All, We bought flat before my marriage and because she is elder to me and we were getting more loan on her income, we bought flat on her name. Now she is married and I am not getting tax benefit so we are doing a sale deed of the flat from her name to my name. The society is unable to decide whether to charge transfer fee of Rs.25,000. Some committee members say because this transaction is between blood relative, real brother and sister there cannot be transfer fee, and few committee members says because it is a sale deed, there has to be a transfer fee. Please let me know if the society can charge 25,000 as transfer fee or not. What does the law say, any specific law number if possible. Thanks in Advance.