The video of men dancing holding guns is from a wedding held in Pakistan in 2020 and has been misattributed to the Taliban.
TV9, a major Indian news channel, broadcasted a video showing Taliban militants celebrating after taking over Afghanistan on August 15, 2021. However, the video was shot in Pakistan and dated back to 2020.
In the video, a bunch of men can be seen dancing with weapons in their hands. A reverse image search of various clips in the video showed that it dates back to March 2021. The same video was also uploaded on YouTube in September 2020, with "Bannu," a city in Pakistan mentioned in the caption. The same video posted by another YouTube user suggests that the footage is from a wedding held in the same town.
The scene shown in the video has nothing to do with the current situation in Afghanistan, as the video was shot way before the Taliban took control of Afghanistan.