Producer Karan Johar announced the film via Twitter on 11 October 2017 revealing that it would be made into a film trilogy. The preparation for the film started in January 2018. In an interview, Kapoor revealed that Mukerji “has spent six years of his life working really hard to make an original story” and that the trilogy would be made over a period of 10 years and refuted rumours suggesting that it is a romantic superhero film. Instead Kapoor confirmed that the film is a “romantic-fairytale in a supernatural format.” and that the film is not something which “doesn’t have truth to it, or which is unbelievable”. Initially the film’s title was rumoured to be Dragon but was later confirmed as Brahmastra. Director Ayan Mukerji explained that the title ‘Brahmastra’ “resonates with the “ancient wisdom, energies and power,”. Mukerji also revealed that it is a “contemporary film with ancient elements.”
Nagarjuna also confirmed that he would be playing a “pivotal” role.Also , Mouni Roy said that she is the ‘only villain’ of the Karan Johar movie .
Director Ayan Mukherjee revealed that the inspiration behind Actor Ranbir Kapoor’s character came from Rumi who also inspired the first look of his character. Mukherji also drew inspiration from Rumi’s work: “love is the bridge between you and everything” to build the foundation of the movie. Later, Mukherji revealed that the Rumi-inspired look was scrapped and Kapoor had gotten a haircut instead.
Bachchan revealed his experience with look tests for the film expressing that it is a “tedious job, sticking removing applying de applying and applying again, until some decision is reached”
The principal photography began in February 2018 with the commencement of the first schedule of the film on 24 February 2018. The first schedule of the movie was wrapped up in Bulgaria on 24 March 2018. The second schedule of filming continued in Bulgaria and then London on 8 July 2018., in London, New York and then in Bulgaria. Extensive shooting started in 1 February 2019 at Edinburgh, Scotland. The final 20 day schedule started in the Ramnagar Fort and Chet Singh Fort in Varanasi on 30 July 2019.