100 Days is a Bollywood film released in 1991. The film is a mystery thriller around the theme of extra sensory perception.
Inspired by the Italian Giallo genre of films. 100 days uses main plot elements from Lucio Fulcis 1977 classic "Sette Note in Nero" [Released as Seven Notes in Black & The Psychic].
The Tamil film Nooravathu Naal  also had a similar storyline.
The film opens with a young woman, Devi [Madhuri Dixit], who gets sudden visions [usually accompanied with a mild panic attack] of incidents and accidents that have not yet happened.
Her college friends Sudha [Sabeeha] and Sunil [Javed Jaffrey] try to help her sort through her visions, but to little avail. Things become interesting when Devi gets a vision of her older sister Rama [Moon Moon Sen] being murdered by a mysterious man in a fedora and raincoat. [The film shows footage of the man as viewed from behind; we do not see his face at this point]. Devi immediately calls Rama [who lives in another city] and is placated for the moment. But her sister is indeed murdered [exactly according to Devis vision]. The murderer drags her body off to a deserted kothi [bungalow] and hides it inside a wall of said bungalow. Rama is reported missing. Devi firmly believes Rama is dead.
Flash forward five years to the present day. Devi moves to her uncles [Ajit Vachani] home where she eventually meets and is courted by millionaire businessman Ram Kumar [Jackie Shroff]. After a somewhat brief courtship, they marry. [Sunil is somewhat dejected; he held an unrequited love for Devi.] It turns out that the kothi belonged to Rams family and was sealed off pending a legal ownership dispute for the past six years [i.e. it was still sealed when the murder happened]. Ram and Devi move into the newly redecorated bungalow and begin their married life.
Devi now gets another vision. The visions are detailed and precise. In this vision, she sees another woman get murdered. She also pinpoints two details: a magazine cover with a horse on it and a video cassette labeled 100 Days. Sunil and Devi visit the magazine office. The editor politely informs them that the next six months covers do not feature any equestrian theme whatsoever. The cassette clue, too, is a dead end: no video store in Bombay carries any such title.
Devi begins delving into Ramas life. Rama was a research scholar; she was working on a thesis about ancient sculptures and temples in India. In Ramas notes, Devi finds a photo of a certain stone image. When she visits the Bombay Museum, she finds that the image is no longer on display. The tour guide explains that it mysteriously disappeared while abroad. The guide reveals that after this incident, the museum security officer Jagmohan and the record-keeper Parvati lost their jobs.
Devi begins tracing them. Jagmohan turns out to be a violent and bad-tempered tough guy and Parvati is a conniving vamp. It is revealed that Parvati videotaped Ramas murder and labeled the cassette 100 Days. And that Parvati is using the tape to blackmail the real murderer.
Devi now gets a stronger vision about her sister. The vision draws her to a wall in the kothi, whereupon she discovers the skeleton in the wall [complete with a necklace that Rama had bought as part of a pair; Devi wears the other one]. Medical investigation reveals that the skeleton is that of a young woman roughly matching Ramas description, but is ultimately inconclusive about the identity of the person. The investigating officer also dispels the uniqueness of the necklace as several identical models are commonly available everywhere.
The sinister connection is exposed when Jagmohan, having heard that Devi is snooping a bit too much, tries to murder her. Devi finds the 100 Days tape with Jagmohan, and after a deadly chase she knocks him into a swimming pool and escapes. When she gets home to Ram, she sees various artifacts around the room [Rams cigarette, a broken mirror and so on] that exactly correspond to her visions. She plays the tape. It is revealed that her sister was murdered by Ram!
Jagmohan appears on the scene and tries to finish off Devi. Sunil comes to help Devi. When they are fighting, Ram intervenes and kills Jagmohan. He then reveals the truth. Many years ago, he was involved in smuggling ancient sculptures out of India. The museum folks Jagmohan and Parvati were his accomplices. They would replace the real images with fakes. Rama was able to identify the fakes and threatened to blow their cover. Ram went to talk her down when Jagmohan [not Ram] hastily shot her from behind. The tape was shot at an angle where Jagmohan was outside the viewing range, making Ram look like the killer. Parvati used the tape later to blackmail Ram.
The film ends with Ram being led off by the police while Devi wearily looks on.
Source : 100 Days Wiki Page