Hi Aditya,
Unfortunately, the application deadline for the last round (round 5) for the MiM 2012 class was 8 days ago. If you mean you wish to apply in 2012 (so for the MiM 2013 class), then you're good and indeed no dates have been released yet.
Here's a quick overview of what you need to be able to apply. You'll need a CV, your transcripts, a GMAT score above 600 (that's the minimum, but try above 650 for safety), a good TOEFL score (or IELTS or Cambridge), two reference letters (ideally one academic and one pro) and very solid essays. Once you get high enough test scores, the essays are absolutely key. They can get you in with a 600 GMAT or keep you out with a 750. In the interview, all you talk about is how your past experiences are being and going to be used to propel you towards your future goals, and how LBS can help you in that process. This, as well as how you are different from other applicants (hint: use lots of details and specifics), must be completely clear in your essays so that admissions will want to meet you in person. The program is very career-oriented, so soul-searching in that area must occur before you apply.
Hope this helps!
Thibs