I think this is very reliable: http://rankings.ft.com/businessschoolrankings/masters-in-management-2013

Thank you for your comment.

According to FT rankings, Aston seems the best option for me. However, I heard that In Asia like South korea, Singapore or Hongkong, many people don't know much about Aston university. Thus, I am concerned about overall reputation. Is there any other option besides Aston ?

Im also thinking about deferring admission, if another university is better choice besides above universities.......
please give me some advise.

Yes, it could be a good idea to defer admission. There are better schools listed in the ranking. As the footnote explains, the top ten schools are on a much higher level:

"Some 200 points separate the top programme, University of St Gallen, from the school ranked number 70. The top 10 participants, from University of St Gallen to Esade Business School, form the top group of Masters in Management providers. The second group, headed by EMLyon Business School, spans schools ranked 11th to 31st. Differences between schools are small within this group. The 20 Schools within the third group headed by University of Strathclyde Business School are similarly close together. The remaining 18 schools make up the fourth group."

Look at schools in the top 31. ESSEC stands out to me because it has a campus in Asia. The LSE and Imperial are very famous. The MiM at London Business School is too young to be in the ranking, but that is also a very serious contenter.

I've never heard of any Aston program that guarantees placements. In any case, this applicant is looking for an MSc program and wants to work in Asia after graduation.

Just curious, why are you looking at UK programs when you plan to work in Asia? There are some great MSc programs in China (Tongji, Shanghai Jiao Tong...) as well as in Singapore (NUS), and Hong Kong...