Margot Robbie has the chops and beauty to play Sharon Tate in a Quentin Tarantino movie about the Manson murders, but Jennifer Lawrence … not so much, at least according to Sharon’s sister.

Debra Tate told us if the Sharon role comes down to Margot or Jennifer … Margot’s the clear choice … and it’s not ONLY because of looks. Sounds like an unkind cut, but Debra explained why she’s not taking a shot at J Law.

According to a report … Tarantino’s putting finishing touches on a script for the Manson project, and both actresses are in the running for roles, though it’s not clear who they’d play.

Debra added she’s yet to hear a peep from Tarantino … which could be a problem because she owns the rights to her sister Sharon’s image and likeness.

Quentin Tarantino is quietly starting to put together his latest project, and is talking to A-list actors for what is promising to be a unique take on the Manson Family murders.

The project, whose title is unknown, was written by Tarantino, who would also direct. Harvey and Bob Weinstein, who have produced and executive produced Tarantino’s previous films, are involved, sources tell The Hollywood Reporter.

WME is said to be in the early stages of shopping the project to studios to co-finance and co-distribute the venture, similar to the way Tarantino and the Weinsteins made the filmmaker’s 2009 movie Inglourious Basterds, which had Universal Studios as a financial and distributing partner. Sources say that Tarantino is putting the finishing touches on the script and that Brad Pitt, who worked with the filmmaker on Basterds, and Jennifer Lawrence have been approached. Studios could receive the package after Labor Day, according to one source. The plan is to shoot in 2018, possibly in the summer.

Script details are scant but one of the stories centers on Sharon Tate, the actress and wife of director Roman Polanski who was murdered by Manson and his followers in 1969.

Manson had ordered a group of his followers to attack the inhabitants of a house in the Benedict Canyon area of Los Angeles, believing it was owned by a record producer who earlier had rejected him.

Over the course of several hours on the night of Aug. 8, the four followers, using guns and knives, brutally killed Tate, who was eight months pregnant, and four other occupants.

In 1971, Manson and members of his crew were sentenced to life imprisonment for these and several other murders committed that summer.

If the Manson-Tate project does become Tarantino’s next film, it will be his first movie based on true events.

Any talks with actors are in the early stages, and one insider said that Lawrence is not considering the Tate role.