KMRL publishes one of the more detailed prohibited-items lists among Indian metro systems, and it's worth knowing before you're stopped at the security scanner.
Luggage limits
Bags are capped at 60 × 45 × 25 cm and 45 kg gross weight. If your bag is oversized, expect it to be turned away at the scanner before you even reach the platform — this isn't a soft guideline, it's enforced at the checkpoint.
What's explicitly banned
- Explosives, compressed or liquefied gases
- Petroleum and inflammable liquids
- Corrosive, toxic, or radioactive substances
- Weapons and ammunition, including CBRN-related items
- Dried or decomposed blood, corpses, carcasses, or human remains
- Alcohol, tobacco, and narcotics — the official list explicitly names ganja
- Lighters, matches, kerosene, petrol, and diesel KMRL's list is unusually specific compared to most metro systems, so if you're carrying anything even loosely related to the above, don't try your luck.
Everyday etiquette rules
Eating, drinking, and smoking are banned on both trains and platforms. Chewing gum and betel leaf are explicitly called out as not allowed too — a small but distinctly local detail worth knowing if you're a paan chewer.
Bottom line
Stick to well within the 45 kg / 60×45×25 cm limit, leave alcohol and tobacco at home or in checked luggage elsewhere, and treat the banned-items list as genuinely enforced rather than a formality.