Billed as "ice-cold" and "manipulative", Nish is introduced as the estranged mentally abusive and controlling husband of Suki Panesar (Balvinder Sopal) and the father of Kheerat (Jaz Deol), Jags (Amar Adatia), Ash (Gurlaine Kaur Garcha), and Vinny (Shiv Jalota).

Since his introduction, Nish's storylines have focused on his attempts to rebuild relationships with his family, the crumbling of his marriage to Suki, a feud with Suki's lover Eve Unwin (Heather Peace), being in a coma during "The Six" storyline, a fling with Kat Slater (Jessie Wallace), suffering from viral myocarditis, learning the truth of The Six's murder and falsely confessing to the crime resulting in his arrest, and escaping from prison.

In September 2024, it was announced that Chowdhry would exit the show ahead of the 40th anniversary celebrations, with the character departing in episode 7006, broadcast on 31 October 2024 after being arrested.

praised Nish for quickly becoming a "memorable rogue" on the show, and Johnathon Hughes of Radio Times commended the character as one of the most heinous in the show's history, Hughes' co-worker Laura Denby criticised Nish for his behaviour and lack of redeeming traits and Amber-Louise Large of MyLondon labelled him as the most divisive member of his family.

With Nish having been declared "one of the soap's biggest villains",[1] Chowdhry has been vocal about how much he enjoys his role, but has admitted concerns about how playing the character could affect his public image.

But in order to ensure that Nish leaves Walford permanently and they may live happily ever after, Suki and Eve Unwin (Heather Peace) begin an affair and conspire against him.

When he wakes, he admits that he cannot remember what happened that night, so Suki tells him a fabricated story about Keanu Taylor (Danny Walters), whom the women later murdered and hid the body of, attacking Nish and running away.

Despite the deal, Nish remains determined to find the truth and invites Suki over for dinner, only to be served with divorce papers which he rips up.

After deciding to give things another try, Nish employs attorney Roger Peel (Ben Jones) to "help" Kat with her divorce from Phil and share of the businesses.

When his family continue to refuse Nish's apologies, he sells the café back to Kathy for £1 in revenge and threatening to write them out of his will.

In early December, Nish pleads guilty to Keanu's murder, but is horrified when he overhears Eve and Suki together during a phone-call with Nugget; he thus realises the two have reconciled.

The night before the wedding, Nish attempts to lure Eve from her hen party to stab her; however, this fails when he suffers a mini-heart attack.

Upon being revived by Nugget and the prison doctor, Nish obtains a dangerous substance and arranges for a taxi to take him to the wedding venue the next day.

[5] Executive producer Chris Clenshaw echoed Chowdhry's excitement for the character's debut since Nish had been referenced numerous times prior to his arrival on the series.

Clenshaw continued in an announcement: "The spectre of Nish Panesar is finally here, and it's been a pleasure welcoming Navin [Chowdhry] to the cast, and take to the role so effortlessly.

[2][3][10] Upon his announcement, Digital Spy's Daniel Kilkelly described Nish as a charming and charismatic character, but it was noted that viewers would quickly notice that he is "ice-cold, manipulative and driven by a need for power and respect".

[7] Nish has been described as "explosive", "troublesome",[5] "evil",[14] a "villain"[15] or "baddie",[16] "abusive",[7] "controlling",[17] and a man who "can't take no for an answer".

[15] In an interview with Inside Soap, Chowdhry teased that "Eve is playing with fire" and that it "would not be a pretty day in Walford" when Nish finds out.

[24] "The Six" storyline unfolded on Christmas Day 2023, where it is revealed that Nish was the body on the floor after being struck across the head with a champagne bottle by Denise Fox (Diane Parish); however, he did not die and was simply unconscious, with the actual death being Keanu Taylor (Danny Walters).

[28] While Nish recovered from his amnesia, he begin a relationship with Kat Mitchell (Jessie Wallace), who had just discovered her husband Phil (Steve McFadden) had cheated on her with Emma Harding (Patsy Kensit).

[29] Commenting on the romantic twist involving Nish and Kat, Chowdhry admitted it was a "surprise" for both him and Wallace, teasing "it's something that will goes places", adding that "there is something quite big coming up" for the couple.

[31] After Kat breaks up with Nish, he calls the police on her cousin Stacey Slater (Lacey Turner) as revenge, a move which Chowdhry considered a "desperate backup plan".

[34][35] Chowdhry added that Nish's primary motivation for going back to Walford was to support his grandchildren because he was imprisoned during the early lives of his own children.

[46] The character was set to return to enact "nuclear revenge" on Suki for going ahead with plans to marry Eve, despite making a deal with her that if he took the blame for killing Keanu, that wouldn't happen.

[51] Upon his first scenes, Lea Dzifa Seeberg of MyLondon wrote that fans were "delighted" that Nish had joined the show, but were puzzled about the reveal that he is the father of Ravi, as many believed Chowdhry looked too young.

[53] In October 2022, Alice Penwill from Inside Soap wrote that, by that point, "Nish has already stirred up life for the Panesars – and the whole of Walford, for that matter".

[55] Sophie Dainty of Digital Spy reported that Nish's "nefarious" actions had "infuriated" fans of the show, noting that many hoped for his comeuppance.

[6][59] He added that he has been somewhat "scared" to play Nish at times due to fears that it will affect his public image, explaining: "There have been moments when we've had scenes and I'll speak to the producer and I'll say, 'I'm going to have to go on the school run and you're making me beat up every woman on Albert Square'".

[61] Johnathon Hughes of Radio Times opined that "nasty Nish Panesar ranks pretty highly as one of the most despicable rogues" in the show's history.

[64] The scene where Nish confesses to orchestrating an attack on Eve's elderly mother was described as "chilling" by Manchester Evening News writer Joe Crutchley.