I would love to help you out. Have you visited the Industrial Organizational Journal site that is mentioned in the forum? The first issue is all about Employee Engagement and has really good articles. Let me know if you cannot find it and I will send you the directions to download the article.
I will email you directly with some other information and advice.
Could you tell me what other countries would be comparable to Thailand in terms of benchmarking and comparing engagement levels? I only speak and write in English. What languages can you converse in (I realize English is one of them)? I ask because I may be able to find you survey sources in the languages you need to use.
Welcome to the employee engagement network. I wish you all the best with your Master's thesis on engagement and I would love to hear about what you are learning and the conclusions you are drawing about engagement in Thailand. Please keep me posted.