Indian School of Business, Hyderabad

Hi, I think matching the schools will be a more productive exercise if we compare them with similar programs.
The programme at IIMs that is most similar to ISB's One Year MBA is IIMs own One Year Full-Time MBA programmes, that like ISB's One Year Full-Time course, exclusively accepts candidates with work experience.
Now before you tell me "but, the PGPX/ EPGP are executive MBA courses" - let me clarify upfront that they are not. These courses despite the odd branding, much like all one-year MBA (INSEAD, Oxford) and two-year MBA programmes (Harvard, Stanford) outside India simply accept candidates with substantial work experience. Read this for more: Don't mistake it for an Executive MBA and this one too: The 3 Questions One Year MBA Grads in India are Tired of Answering.
As India's first globally accredited MBAs the One Year MBA at IIMs along with ISB's MBA is the first MBAs from India to have made a mark on the Financial Times Global MBA Ranking. More on this here: IIM A's PGPX Ranked No. 2 MBA in the World for Career Progression: Financial Times 2015 MBA Ranking
The two-year PGP at IIMs is in fact accredited as an MIM and not an MBA globally for this reason. (read this for more on this: IIM Calcutta bags AMBA accreditation & IIM C's PGP ranked 13th in Financial Times MiM Ranking 2014). MIM's are management programmes targeted at candidates with 0-3 years work experience as opposed to MBA programmes that recruit candidates with 3+ years of work experience.
So now that we are comparing similar programmes here is an exhaustive and excellent analysis of ISB's One Year MBA vs IIM B and IIM C's One Year MBA: IIM B vs IIM C vs ISB - Which one is right for you? which should clarify many of your doubts. As the article suggests, the choice is a personal one and depends entirely on your aims.