Please check the Meeting Room Product record and ensure that the following fields have been configured:
Capacity - meaning the number of people that the room can accommodate.
Reservations Product Group - When selecting the Product Group for your Meeting Room record, please make sure that it is marked as a Reservations group. Learn more about Managing Product Groups.
Portal Availability - Please go to Additional Options, at the bottom of the page, and make sure that "Can book on Portal" is ticked.
Style / Layout - Select the style of the room so that the Portal can display it, because there is an option through which your clients can select the layout.
Start Dates - if you meeting room has a start date after the date you are trying to book, then it will not display in the search results
Learn more about Setting up Meeting Room Products.
Please Note:
Your Portal Meeting Room Settings (Settings > General > Portal > Meeting Rooms) allow you to hide the room layout selection dropdown on the booking page.
If you choose to do so, please set the Room Style / Layout to Boardroom. This is mandatory, otherwise the room will not be displayed onto the Portal, even if another layout is selected.