There would not be any tax towards gifted property as such,provided certain conditions are fulfilled as follows:

1)The income derived from the house by your mom should be tax paid,if it was exceeding the threshold of exempted income,in the previous asst.yrs.prior to gift.

2)The proof of ownership by your mom should be documentarily evidenced.

3)You must have been clubbed the interest on the amount lent to your mom,in your annual income.

4)Does your mom have any other sources to repay your loan or not.If not,then we assume that the loan amount was returned through gift.So in this case,the property value thus gifted should be