On the same tweet, a user replied that the video is not from Kashmir but Syria.
We used the invid tool to extract keyframes and did reverse image search on Google. We found a longer version of the video on Youtube which was uploaded on 6th Dec 2013 which clearly proves that the video is at least 6 years old.
However, context about the video and its location is not mentioned in the video description. You can watch the full video here.
Video doesn't give any clue about the location as only trees and empty fields can be seen in the whole video. However, the language spoken by the men in the video is neither Kashmiri nor any other Indian language which proves that the video can't be from Kashmir.
This further proves that the audio in the viral video has been superimposed.
Screengrabs featured in Syrian Blogs
Google reverse image search of one of the keyframes led us to two different blogs where it was claimed that the video is from Syria. A blog 3omalasyr.wordpress.com has claimed that the video is of Shabiha (a term for state-sponsored militias of the Syrian government). As per the blog post, the video was captured in Idlib city of Syria, a clip of which was leaked in 2012.
Another blog post syrianchange.wordpress.com has used the screengrab of the video. As per the blog post, the video clip was broadcasted by activists and was described as a leak. The video shows a number of soldiers of the Asadi regime(referring to Bashar al-Assad, President of Syria) cut off the ears of the martyrs of the Free Army.
Just from the video, it is not possible for us to determine whether the video actually belongs to Syria. However, the video can't be from India since the language in the original video is not from India.
We tried to find out reports from pre-2012 about such video but couldn't find any. It is highly unlikely that a video from India was used by Syrian revolutionary but wasn't covered by any India media or separatist outlet.
Considering all the information available, we can confidently say that the video is not from India.
An old video unrelated to Kashmir is being shared as atrocities by Indian army on Kashmiris. Several blog posts published in 2012 had claimed that the video is from Syria. We couldn't conclusively establish whether the video is from Syria or not but it is certain that the video is not from Kashmir or any other part of India since the language spoken by them in the original video is not an Indian language.