In general, children under the age of 5 years old are allowed to travel for free on Indian trains. However, it’s important to note that this policy can vary depending on the specific train and class of travel. Here are some general guidelines:

1. Indian Railways: Children below the age of 5 years are considered “infants” and can travel for free on Indian Railways trains. They don’t require a separate ticket or berth, but they must share the seat/berth of an accompanying adult. It’s advisable to carry age proof documentation, such as a birth certificate, as it may be required for verification.
2. Reserved Classes: For higher classes like AC 1st Class, AC 2 Tier, and AC 3 Tier, where separate berths are allotted, children under 5 years are still allowed to travel for free, but they won’t be assigned a separate berth. They can share the berth of an accompanying adult.
3. Unreserved Classes: In unreserved classes, such as General or Sleeper Class, children below the age of 5 can travel for free but without a separate seat or berth. They can share the seat/berth of an accompanying adult.

It’s worth mentioning that if you prefer your one-year-old child to have a separate seat or berth, you may need to purchase a child ticket. Child fares are applicable for children between 5 and 12 years old. The specific rules and fares may vary, so it’s recommended to check with Indian Railways or the respective train operator for the most up-to-date information and to ensure compliance with their policies.

Additionally, it’s important to consider the comfort and safety of your child during the train journey. Carrying essential items like food, water, diapers, and comfort items is advisable to ensure a smooth and pleasant travel experience for your little one.