Answer:
Protection and conversion to Catholicism.
Step-by-step explanation:
The Spanish were expected to protect the Indians, because shortly after the Spanish conquests, they were dying often, due to hard work and disease.
The Spanish were also expected to convert them to Catholicism. This is because they considered Catholicism to be the only true religion, and that without conversion, their souls would not be saved (in the divine sense).
In exchange for protection and religious conversion, the Indians had to pay tribute to the Spanish, either in the form of crops, or gold and silver.