SOAS is a preparatory course for international students who do not meet the requirements of the master's program. Applicants need to provide their academic transcripts to prove their academic ability. Generally speaking, the average score of an applicant needs to be above 80.
Therefore, if you graduated from the UK with a master's degree and meet the entrance requirements of the master's program of the School of Asian and African Studies of London University, you can apply for the postgraduate program of the school.