Vinay, i believe that your mother died intestate, i.e. without a will right? In that case, the property will devolve both upon you as well as your father. So even if you do have to make a gift deed/ relinquishment deed, the same will only be for 50% of the property.
Since your divorce matter is presently pending, the advise given by your lawyer seems ideal so as to not draw the Court to the conclusion that in order to deprive your wife, you deliberately transferred the same to your dad.
However, you had previously mentioned that the rents were credited held jointly by you and your parents. What is the position of that account? Is your wife aware of this account?