The film chronicles the life of Bollywood actor Sanjay Dutt, notably focusing his drug addiction, arrest for his suspected association with the 1993 Bombay bombings, relationship with his father, and acting career.

Ranbir Kapoor stars as the title character with an ensemble supporting cast including Paresh Rawal, Vicky Kaushal, Manisha Koirala, Anushka Sharma, Dia Mirza and Jim Sarbh.

The Supreme Court of India delivers its verdict regarding the 1993 Bombay bombings and sentences Sanjay to 5 years jail term for violating the Arms Act, 1959.

Back to the present, when Zubin on being confronted by Winnie rebuts her comments with a revelation about Sanjay's best friend severing ties with him, she realizes the next chapter may have something to do with a now-estranged Kamli, currently a millionaire, who she tracks down to New York.

For possession of illegal arms supplied by the D-Company supposedly to be trafficked for protection during potential communal rioting after the bombings, Sanjay is arrested in 1993, convicted and sentenced for five years under the Terrorist and Disruptive Activities (Prevention) Act (TADA), threatening his career.

Winnie too, considers dropping the book due to her complicated feelings over the subject matter, until Manyata sends him an audio clip featuring Sanjay, which pushes her to realize Kamli's account may have been lopsided.

[22] In an interview with Daily News & Analysis, Hirani revealed what eventually prompted him to create a film based on Sanjay Dutt's life: "He was lonely.

At first, Chopra was of the opinion that "it was hogwash... but when we started researching all that he’s said — from the 308 girlfriends he had to how he begged on the streets of US for the money to buy a bus ticket — we realised that everything he had told us was true!".

He stated that "It will talk about human flaws, the emotional father-son story (between Sanjay and the late Sunil Dutt), his relationship with his best friend, with the women in his life.

[26] In an interview with Rajeev Masand, Hirani disclosed that the story-telling procedure was "challenging as it's not a story of an achiever" as most biopics are based on a heroic personality, yet Dutt is known for his tragedies and losses.

"[27] Kapoor himself also stated that he "knew that there is a fine line between mimicry and representing someone who is loved by so many people" which is why "it took us six to eight months to get ready... to prep, do the prosthetic tests, acting and character rehearsals.

[46] To build his body like Dutt's, Kapoor revealed that it required "sacrifice" and "discipline" as he "was having 8 meals a day, waking up at 3 in the morning to drink a protein shake.

"[54] He also revealed that he went through a "huge physical transformation" by losing weight to "look like a lean young Gujarati guy to an aged man of the present time".

[citation needed] Dia Mirza however, stated that she prepared to play the role of Dutt's wife through "workshops and look tests" but also by studying some of the "news clips released around the time" as well as "her interviews" and "body language".

[69] The film's soundtrack features 6 songs composed by A. R. Rahman, Rohan-Rohan and Vikram Montrose while lyrics are written by Irshad Kamil, Shekhar Astitwa, Puneet Sharma, Rohan Gokhale and Abhijat Joshi.

At the trailer launch Hirani told that the character of Anushka Sharma is actually a comprised role of him and the writer, Abhijat Joshi showing that how they both collected the whole story about Sanjay Dutt .

[citation needed] Aside from poster releases, marketing was also successful through "Sanju-style lip sync and face filters and post videos to win prizes" across social media.

[86] Kapoor also promoted the film by making a rare appearance on social media as he took over the Twitter handle of Fox Star studios and was involved in a live tweet session with fans and shared personal childhood pictures of himself during Father's Day.

[74] Shikha Kapur, CEO of Fox Star Studios stated that the marketing "objective was to build conversations and scale" without [defining the film's] target group by age and geography but by affinities and behaviours online.

He also mentioned that "making Dutt appear flawed, yet sensitive and relatable is also a means to reach out to a generation for which the actor is past his prime" and to "drive entire families" out to watch the film.

[121] In Dubai, the government allowed cinemas to remain open for 24 hours on Friday and Saturday to prevent crowd frenzy, causing shows to start as early as 4:30 am.

[127][128] Swetha Ramakrishnan of Firstpost praised the performances of the cast, especially Kapoor, further writing, "the film doesn't attempt to decode Sanjay Dutt or justify his life.

"[129] Taran Adarsh of Bollywood Hungama gave the film four and a half stars out of five and wrote, "Sanju is an entertaining saga that blends emotions, humour and drama in adequate doses.

[130] Meena Iyer of Daily News and Analysis similarly rated the film four and a half stars out of five, stating that "it’s an emotional roller-coaster that will give you the satisfaction of having read a bestseller.

"[131] Divya Solgama of Bollywood Times gave the film 4.5/5 stars stating that "Sanju’ is an emotionally enriching experience which every cinema lover should witness".

[134] A reviewer for India Today writes, "Director Rajkumar Hirani, who has also co-written and edited Sanju, has taken more than a few dramatic liberties, but it feels refreshingly candid."

[144] Nandini Ramanath of Scroll.in was impassive about the film, writing, "In its relentless quest to offer absolution, Sanju is no better or worse than many other biopics that have flooded Bollywood over the past few years.

"[146] Similarly, Mike McCahill of The Guardian criticised how "this three hour hagiography simply blames everyone else for his troubles" though praised Kapoor for being "a lightweight film’s strongest suit".

[147] Shilpa Jamkhandikar of Reuters similarly praised Kapoor stating that what is "bearable is Hirani’s leading man and his chameleon-like ability to transform himself into various avatars" and also criticized the script as it "stretches too long and resorts to melodrama over substance".

[148] Mary Gayen of The National however praised the film giving it 3.5/5 stars, stating that Hirani's "direction is very matter of fact in relation to the incidents, but very thorough with the feelings expressed by the main characters.