Mop all rooms and not go on rugs:
Firstly, you can go into the map, then select the carpet. You can choose the carpet's shape(round or rectangular). Once you have completed all the steps, select the No Entry option. Thus, your Deebot will avoid mopping or sweeping those areas where you placed carpets.
Then to just vacuum the rugs?
You can go back to carpet settings, select the carpets, then select vacuum only.