EDUSWAMI ANSWER
The quality of some 1 year MBA programs offered in India is at par with some of the best MBA programs offered overseas. This often leads to a toss up choice between the two with some candidates.
The first aspect to consider is the vast cost differential. The fee of a world-class 1 year MBA in India such as the one offered by the Indian School of Business is around Rs 30 lacs. On the other hand, a 2 year program of comparable quality in a developed market like USA, Europe, or SEA would cost around Rs 70 lacs (both years combined, tuition only) [recheck this number].
The second aspect is your own profile. Candidates with more work experience would benefit more from a the shorter version because they can assimilate the concepts much faster, with lesser effort, and incur only half the opportunity cost. Apart from the pace, there is little difference between the 1 year and 2 year options in terms of rigour, depth, quality, content, and level of knowledge gained. In fact, the contact hours (i.e. amount of time spent in the classroom) is just about the same between the two in most programs. The learning experience in the shorter version is enhanced by the real life experiences that the students bring to the classroom and the ease of correlating academic concepts with real life settings.
The third aspect is location preference. While global placements are a real possibility in a quality 1 year program offered out of India, the higher probability is always of getting a job in the country in which you complete your program. This is a result of local physical presence, the network that you develop while doing your MBA, and very simply recruiter preference.