Need information regarding transfer of flat in legal heirs​ name

I am the only legal heir to my parents, my father is no more & mother 80 is hail & hearty. Our society members are requesting all members to get a gift deed done to transfer the flat in the legal heirs name stating that it will be a very cumbersome process after the death of parents to include the legal heirs name in society records & transfer the flat in legal heirs name. Please guide if the above os true & what is the correct procedure to transfer the flat in one's name being the only legal heir after death of parent or property (flat) owner. What would be the approx cost & time taken in this entire process.