The live operatic musical event saw 1000 singers and instrumentalist coming together to perform three songs from the show's album, which has been composed by Pritam.
Guinness World Record adjudicator Swapnil Dangarikar announced that "The Forgotten Army" now holds the record for the largest indian cinematic music band.
"It was a spectacular performance with the highest level of proficiency. It's my great pleasure to be present here to be able to see and listen to the largest indian cinematic music band," he added.
Present at the event were musician Pritam, Kabir and the cast including Sunny Kaushal, Sharvari Wagh, Rohit Bharadwaj, and TJ Bhanu.
Kabir hailed the performance and said it was able to "capture the very spirit of the Azad Hind Fauj".
Pritam said he was excited to have witnessed a "unique live performance".
"This Republic Day, let's all take a moment to understand the forgotten history and the sacrifice of the Indian National Army," he added.
"The Forgotten Army" started streaming on Amazon Prime Video from Friday