Fare rules can be found on the flights page during online booking. Once you are presented with the available fares for your flight, click on the price you will see a summary of the fare rules under each category of fare. Once you click on "Select" to select the fare you will purchase, click on "Fare Rules" which will give you the detailed fare rules for the itinerary selected. It is always advisable to read the detailed fare rules to be aware of the rules attached to your ticket.
For further enquiries contact your local offices, contact details can be found in the following link https://www.qatarairways.com/en/worldwide-offices.html