The actual home "Tara" used in the film 'Gone With the Wind' is located where?

The fictional plantation found in Margaret Mitchell's 1936 novel "Gone with the Wind", was located near Jonesborough (now Jonesboro), Georgia. Interestingly, after filming concluded, the façade of Tara sat on the "Forty Acres" backlot of the former Selznick Studios as it changed ownership to RKO Pictures and then Desilu Productions. In 1959, Southern Attractions, Inc. purchased the façade, which was dismantled and shipped to Georgia with plans to relocate it to the Atlanta area as a tourist attraction.

https://en.wikipedia.org/wiki/Tara_Plantation#Movie_Set_Gallery

Although people still arrive in Atlanta expecting to visit Scarlett’s estate, not a single scene was shot in Georgia. Virtually all the movie was filmed at what was then the Selznick International Studios.

You'll probably recognise it as the mansion seen before the titles of classic David O Selznick productions. It's at 9336 Washington Boulevard between Ince and Van Buren, Culver City. The white, classical Washington Boulevard frontage of the studio was used, with a little matte painting, for the entrance to 'Twelve Oaks'.

http://movie-locations.com/movies/g/Gone-With-The-Wind.php

Tara, the fictional plantation found in Margaret Mitchell's 1936 novel 'Gone with the Wind,' was located near Jonesborough (now Jonesboro), Georgia. As the locale of the final, decisive defeat of the Confederate defenders in the Battle of Jonesborough, Jonesboro and its surrounding farmland realized historical significance.

In the novel 'Gone with the Wind,' the plantation was founded by Irish immigrant Gerald O'Hara when he won a section (640 acres) of land from its absentee owner during an all-night poker game. Very much an Irish peasant farmer rather than the merchant his elder brothers (whose emigrations to Savannah brought him to Georgia) wanted him to be, Gerald relished the thought of being a planter and gave his mostly wilderness and uncultivated new lands the grandiose name of Tara after the Hill of Tara, once the capitol of the High King of ancient Ireland. He borrowed money from his brothers and bankers to buy slaves and over several years turned the farm into a very successful cotton plantation.

https://en.wikipedia.org/wiki/Tara_Plantation

The Hill of Tara (Irish Teamhair na Rí, "Hill of the King"), located near the River Boyne, is a long, low limestone ridge that runs between Navan and Dunshaughlin in County Meath, Leinster, Ireland. It contains a number of ancient monuments, and, according to tradition, was the seat of Árd Rí na hÉireann, or the High King of Ireland.

https://en.wikipedia.org/wiki/Hill_of_Tara