Rileen (Saif Ali Khan), receives news of his growing stomach cancer, which is at the last stage. He is left heartbroken, but remains quiet in front of everyone. He decides to live life to the fullest, by smoking and taking LSD from a friend, but yet remains unhappy.

His engaged brother Angad (Akshay Oberoi) is getting ready when he receives a call from his ex-girlfriend, Selina (Amanda Rosario) to a hotel. Angad sets out to meet her along with Rileen under the excuse of a haircut.

In the next story, we see Tara (Sobhita Dhulipala) packing her bags to pursue higher studies in the US, while her boyfriend Zubin (Kunaal Roy Kapur) is trying to convince her to change her plans. Hours before flight, both of them attend a birthday party, but soon the police raid the place. Tara is nervous as her flight leaves in two hours, but she can't leave as the police have locked the place down. She manages to escape with her friends along with Zubin in a car. In the car, Zubin and Tara have a heated argument over Tara kissing a guy, Tara loses control and hits a motorcycle killing two guys. Tara feels guilty, but leaves when Zubin and her friends advise her not to go to the cops.

Meanwhile, Rileen is hallucinating due to the LSD. He meets a transgender Sheila (Nary Singh) and coolly tells her that he wants to see her "Southern Hemisphere", with no touching or feeling, and succeeds in doing so. Rileen becomes happy and decides to fulfil other things on his bucket list.

The next story is of two goons who wants to make it big, Mafia (Deepak Dobriyal) and Rahmat (Vijay Raaz). They plot a plan to extract money from their own boss Raza (Asif Basra) and cook up a story. Meanwhile during a party, Ustad (Neil Bhoopalam) a guy who has helped Raza a lot gets killed on the road by two motorcycle borne assailants. Mafia and Rahmat witness the crime.

Angad learns that Selina is just using him and feels guilty about cheating Neha (Amyra Dastur),the bride. Angad meets Neha and talks to her. Angad learns that Neha is a very nice girl he can get and both of them hugs each other and gets ready for marriage.

Mafia's greed pushes him to kill Rahmat and he takes the entire money. He then shoots himself in the abdomen and tells Raza that someone has robbed their money and killed Rahmat and in that fight Mafia too got injured. Raza doesn't believe Mafia and is on the verge of killing Mafia, but leaves him. Mafia walks onto the road.

Rileen meets the wedding photographer Rakhi (Isha Talwar) and tells his son too had a birthmark like her on his elbow. Rakhi asks him his name but he states that "People just meet, tell each other their names and then go away, which of no use. He also tells her about his growing cancer. Rakhi somehow comforts Rileen and they kiss each other. On being asked "What does he mean to her?", she replies "I don't know!" He happily laughs and tells her his name Rileen.

Tara checks into the airport while Zubin asks her not to think of the horrific night. Tara feels very guilty and decides to approach the police and file an FIR, but the police asks her not to do so as the two guys who were killed in the accident were underworld shooters who killed Ustad. Tara meets Zubin waiting for her. She gets to know he truly loves her and proposes him for marriage and then kisses him.

Rileen marches into the dance ceremony of the marriage where everyone is dancing mindlessly along with Angad and Neha. Rileen dances like a mad fellow takes out his gun and scares everyone. He fires two bullets in the air vertically, one of the bullet rises high up in the sky then goes down hitting Mafia on head, thus killing him.

In the final scene Rileen looks into the camera and screams as the second bullet has hit his foot.

• Saif Ali Khan as Rileen
• Akshay Oberoi as Angad
• Isha Talwar as Rakhi
• Sobhita Dhulipala as Tara
• Kunaal Roy Kapur as Zubin
• Deepak Dobriyal as Waris
• Vijay Raaz as Rehmat
• Shivam Patil as Jehangir
• Amanda Rosario as Selina
• Shenaz Treasury as Ayesha
• Asif Basra as Raza
• Nary Singh as Sheila
• Amyra Dastur as Neha
• Neil Bhoopalam as Omelette/Ustad
• Bugs Bhargava Krishna as Dr Rajendra

The music of Kaalakaandi is composed by Sameer Uddin and Shashwat Sachdev while lyrics have been penned by Anvita Dutt and Akshay Verma. The first track of the film titled as "Swagpur Ka Chaudhary" which is sung by Akshay Verma was released on 23 December 2017. The music album was released by Zee Music Company on 27 December 2017.

Kaalakaandi received mixed response from critics upon its theatrical release.

Saibal Chatterjee from NDTV gave the movie 3 out of 5 stars stating, "Kaalakaandi may not be for all palates, but the film has enough spice for those in the mood for an off-the-beaten-track Bollywood experience".

India TV gave the movie 3 out of 5 stars, stating that the word Kaalakaandi is Marathi slang for "when everything goes disastrously wrong" and described the lead character as "outrageously humorous yet utterly sensitive"."

Rediff.com gave the movie 3 out of 5 stars stating, "Saif is a hoot in Kaalakaandi".^[7]

Meena Iyer from Daily News and Analysis gave the movie 2.5 out of 5 stars stating, "Saif Ali Khan's 'Kaalakaandi' is worth a try, if you like your cinema experimental and edgy".^[8]

Renuka Vyavahare from Times of India gave the movie 2.5 out of 5 stars stating, "What begins as a promising and edgy thriller soon runs out of gags, gas and gravitas".^[9]

Sweta Kaushal from Hindustan Times gave the movie 2 out of 5 stars, praising Saif Ali Khan for his performance, despite the script being half-baked.^[10]

According To Firstpost, Saif Ali Khan is funny as hell in Kaalakaandi but the film lacks fizz.^[11]