Well if you have a degree from American University and if the medium of instruction was English, you will not need the IELTS exam or TOFEL exam, because both exams are the English proficiency test exam only students from non-English speaking countries are required to take the test.
The students who have completed their graduation need 6.5 not less than 6 bands in each module( Reading, writing, speaking, and listening ) for applying to SDS category, and for Undergraduate students, you will need 6 bands in each module not less than 6 in each module.