The National Society of Film Critics named Akira Kurosawa's ''Ran'' best picture of the year today at the group's annual meeting here, continuing a trend in which critics have generally praised imports over domestic films. ''The Purple Rose of Cairo'' and ''Prizzi's Honor'' tied for second place.

Jack Nicholson, who portrayed a hit man in the black comedy ''Prizzi's Honor,'' easily won the best actor award. Runner-up was William Hurt for his role in ''Kiss of the Spider Woman.''

The best actress award was won by Vanessa Redgrave for her performance in ''Wetherby.'' Jessica Lange came in second with her portrayal of country singer Patsy Cline in '' Sweet Dreams.''

John Gielgud won best supporting actor for his roles in two films this year, ''Plenty'' and ''The Shooting Party.'' Runner-up was William Hickey for ''Prizzi's Honor.''

The award for best supporting actress went to Anjelica Huston for her portrayal of Mae Rose Prizzi in ''Prizzi's Honor.'' Runner-up was Mieko Harada in ''Ran.''

''Shoah,'' Claude Lanzmann's 9-hour film on the Holocaust, easily won the category for best documentary. Placing second was Michael Apted's ''28 Up.''

A surprise winner was ''Lost in America,'' which landed best screenplay honors for cowriter and director Albert Brooks. Runner-Up was Woody Allen for '' The Purple Rose of Cairo.''

The National Society of Film Critics, which has 43 members nationwide, was founded in 1966 as an alternative to the New York Film Critics Circle. The society's membership includes alternative as well as mainstream newspapers and magazines.

In year-end awards voted on last month by Los Angeles and New York film societies, Terry Gilliam's ''Brazil'' and John Huston's ''Prizzi's Honor,'' were accorded best picture honors, respectively.