Indian Railways — confirmed seat occupied by others

Website:

www.indianrail.gov.in

Hello indian railway,

This incident happened on 24th feb.2018. Details are
Train no - 18605 / rnc jyg exp
Class : sleeper class
Pnr no. : [protected]
From : jsme to : ski

I've booked e tickets for my old parents who travelling from jsme to ski.
Actual time of train was 23:05 but it was late by 2hrs that day. My parents informed me that 2-3 passengers are already occupied their reserved seats and not ready to give seats (Even not adjusted). I've suggested that please try to reach t. C. And informed him. But for your information, there was no tc came in that train and my old parents (73 & 66) were standing all night.
The train was arrived in morning so they just moved out from there.
Please suggest me where i can file a case regarding harassment or whom i've to contact.
Thnx