Protests from the National Coalition of American Nuns have forced the New York Times to modify advertising appearing in the paper for the film, "Nasty Habits."

The sisters have thus far had no effect on the showing of the film itself, which they say "will inflict incalculable damage to the image of credibility of religious women."

The film, adapted from the Muriel Spark novel, "The Abbess of Crewe," is a satire of Watergate, with the hanky panky of the later Nixon years translated to the machinations of a couple of cinema nuns vying for the post of abbess.

The ad to which Sister Ann Gillen, a member of the executive board of the coalition, took exception, showed a woman in nun's habit, tape-recorder dangling from her belt, her long skirt held up to mid-thigh to reveal shapely legs. The pose does not appear in the film.

In the revised ad, the knee-length skirt stays put.

Sister Gillen also took exception to reviewer Rex Reed's rationlization of the satire because, he said, "we all know nuns are doing all sorts of unsavory things in real life."

In a letter last week to sisters around the country, Sister Gillen proposed that religious order file damage suits, with any funds won "to be used to finance charitable works for women across the nation . . . After all, are not all women abused by the attacks on any one of them?"

Contacted by phone in her Chicago office earlier this week, she admitted that there was little likelihood that suits actually would be filed. She said, however, that spokeswomen for other groups of nuns share her indignation.

"I don't see why Watergate should be saddled onto the sister," she said.

Quite a different kind of protest to quite a different kind of film has drawn its own protest in the affair of Dr. Bob Jones III vs "Jesus of Nazareth," the six-hour, made-for-TV film.

Having seen neither the film nor the film script, the fundamentalist Jones condemned it, and mobilized a letter-writing campaign against it, based solely on a published interview with the film's director, Franco Zeffirelli, which Jones came across in a movie magazine.

The letter-writing campaign prompted General Motors, which had spent an estimated $4.5 million on the production and TV rights to it, to with draw as sponsor and wash its corporate hands of the whole thing.

The bad publicity also sent NBC, which will begin a telecast of the film Palm Sunday night, into a flurry of screenings for religious leaders, virtually all of whom have come away with praise for the film.

From Campus Crusade director Bill Bright to the Rev. Patrick Sullivan of the U.S. Catholic Conference; from a Twin Circle staff writer to Evangelist Billy Graham, the response to actual viewing of the film has been approving, with varying degrees of enthusiasm.

Paul M. Stevens, radio-TV man for the Southern Baptist Convention who had earlier expressed public doubts, about the film without having seen it, proclaimed after seeing it "the greatest religious film I ever saw." He noted that criticism of the film without seeing it "places these people in the same point as the enemies of Christ in this film."

The Rev. William Force of the National Council of Churches praised the film and attacked Jones as "un-American" for his attempts at precensorship of the film.

"I am frankly embarrassed that a person such as yourself would act in such an uniformed, biased and irresponsible manner in the name of Christianity," Fore wrote Jones.

Collins-Word press in Cleveland produced a coffee-table style book based on the film, with color stills and text by Bible scholar William Barclay, which has gone into three printings. When the criticism of the film mounted, the publisher had threats of boycotts.

Perhaps the last word should belong to Zeffirelli, who said he was "deeply upset and hurt that men who have dedicated their lives to the study and the spreading of the Christian doctrine should allow themselves to prejudge a film which in its true essence is utterly unkown to them."