Earlier there was a major difference in the placement scenario of both the courses and institutes. For the IM course, one had to study at a foreign business school, with which MDI has a tie-up during the second year, and manage your internship on your own. Moreover, they let you sit for the final placements only.
On the other hand, at IIM you can avail of the summer placements, and PPO and then even sit for final placements.
Fortunately now, the PGPIM is a 2-year residential course at MDI Gurgaon campus only, with summer and final placements happening along with the PGP students. Through this, it has overcome its shortcomings of average final placements and is a much better option than IIM Trichy.