It is unclear that any international student graduating with an MBA can convert their Tier 1 to a Tier 2 visa with a job within four months. In the best of circumstances, even a domestic graduate can take more than four months to get a job.

Complicating the situation is British Prime Minister plan to dramatically reduce the number of Tier 2 visas. If passed, there will only be a third of Tier 2 visas granted than prior years.  (Source: https://www.theregister.co.uk/2016/10/18/may_blocked_plans_to_bring_in_more_indian_it_workers_cable/)

The prudent student should begin looking for a position immediately on entry to the MBA program and relentlessly and act as if the Tier 2 visa will be granted. Employers are more likely to respond favorably to a positive attitude rather than a negative one.