Yes, in most cases you can put several rooms into a single booking through our hotel booking API. When you search, you tell the system how many rooms you need and who is staying in each one, including the adults and any children, and the results come back priced for the whole party rather than for just one room. When you confirm, you normally get one booking reference that covers all the rooms, which is far easier for your staff to track than making the same booking over and over.
How far this goes does depend on the supplier behind the room. Some suppliers happily take a good number of rooms in one go, while others set a limit per booking and expect anything larger to be split or handled as a group request directly with the hotel. A few also insist that every room in the same booking shares the same room type, the same board basis and the same dates, so a party that wants a mix of twins and doubles may end up as more than one booking even though they are travelling together.
Availability matters too. A hotel may show a room as free for one guest but not have enough of that same room type left for your whole group, so the price per room can change or the option can drop out once you ask for more rooms. This is normal and it is the hotel deciding what it will release, not a fault in the software. Where a supplier cannot take everything in one booking, the system will tell you rather than quietly book part of the group.
The sensible next step is to try a realistic group search in your test environment, with the room split you usually sell, and see how each of your connected suppliers responds before you promise anything to a customer.