Transferring property to Father and pay rent to parents to save tax

I have bought a property in Mumbai few years ago. Earlier there was an EMI on the flat but now its over. Now I own to property so I am not able to save the tax on HRA. What I am planning is to transfer property to my father & mother and then pay them rent to save the significant amount of tax (as my parents are senior citizens and they dont have any other income ) I have couple of questions related to this : 1) Do I have to register the property on my parents name ? 2) is it possible to do it without stamp duty /registration charges, like some gift deed etc ? 3) Also Maharastra has recently reduced the Stamp duty charges so will it be applicable in this case as well. 4) Do you see any issue if I take this approach ? 5) can there be any complications in property transfer to me once my parents life time is over ?