Apartment as gift to relative

Hi,

My wife and I have a under construction flat that is booked under joint name of my wife and me. We have paid around 80% of the payment to the builder (50 lacs out of around 62 lacs) . My wife and I want to gift the property to my mother. The remaining 20% of the pending amount would be paid by my mother.

From various other posts, I got to know that this does not involve any taxation. Can you please tell me whether there would be any tax liability on me or my wife on the rental income that this house may generate in future after completion ?

Thanks !