I can �t help much with the latest methodology, but I can help with a few questions to narrow your focus. EFL/ESL is a very broad subject, but it can be broken down well.
1) What is your favorite area of English instruction: reading, listening, writing, or speaking? As subsets of writing, you have mechanics such as punctuation and capitalization, and spelling. As subsets of speaking, you have pronunciation, intonation, and fluency. Do you especially like grammar? Vocabulary and word formation?
2) What age level of learners are you most interested in? Very young children, school-aged children, teenagers, or adults? Different approaches are needed for different ages.
3) What techniques have worked well for you in the classroom? Do you prefer a drill-based approach, whole language, whole body integration, games and humor, etc.?
4) What resources are available for teaching? I know many classrooms are incorporating a lot of technology, but there are also many schools that can �t afford such technology. Some schools can �t even afford books, much less computers and iPads. What do they do?
5) What impact does the culture play on English learning? Who learns English better, students in conservative Islamic schools, or students in more liberal secular schools? How does exposure to English-language media affect students � interest in learning English?
In other words, pick a subject that appeals to you and hope that your advisor will approve. If not, you may want to see if you can get a different advisor. If not, then ask your advisor for guidance in a subject. We really can �t�and shouldn �t�pick a topic for you.