A group of 10-15 people put music and danced in the train coach and in stations, yet nobody even the TTE took action

So I was traveling in JAM TEM Express (19578) from Thrissur to Trivandrum (Kerala) today. A group (around 10-15 people )of wannabe cool guys converted the reserved sleeper coach into a partyhouse. They put music from a huge speaker and danced till I left the train (6ish hours) Fun fact is when the train stopped in major stations such as Ernakulam, Alleppey and Quilon, they stepped down to the platform and did flash mobs, even overriding the station announcement to the passengers. What made me baffled is that TTE passed through these group like nothing happened. Maybe these guys were a bit muscular so I give TTE the benefit of the doubt. Also the railway police never came to check the coaches. What can I do to complaint these incidents in the future. I didn't tried to record the incident, given I was traveling alone and don't want to get into any trouble.