It is recommended to first completely integrate the hotel level mappings before starting room mapping integration. 

This way you will be able to get the complete content of the hotels along with the assigned Vervotech ids. This will be helpful when you create the requests for room mapping. The Vervotech id and room codes that you get in the property level mapping (hotel mapping) are a part of the room mapping request, and in this way, it will become easier for you to generate the requests for room mapping. 

If you start room mapping first then hotel related information will not be provided in the request query. As hotel mapping plays a base role in room mapping, therefore, it is recommended to integrate it first hotel mapping first and then room mapping.