Yes, you can easily get into BA Programme St. Stephens through Christian Minority Quota provided you clear the interview phase. The cutoff (BA Programme.) for Christian Minority Quota in St. Stephen's range from 78-88% depending on the type of Christian Minority. So, since you already have 92.7% in the BFS, you only have to clear the interview. The interview of St. Stephen's college is based on your domain as well as critical thinking abilities. You have to be clear about your vision of pursuing this course and have relevant knowledge about the field. You will be asked questions about your views on particular issues and subjects. The right way to approach the interview is to remain calm and confident. And, wish you all the best for future.