When comparing IIM Rohtak to IMT Ghaziabad, the preference varies from person to person. IIM Rohtak is unable to match IMT G's history, its extensive network of corporate connections, and its superior learning environment and segment of the population.
IIM Rohtak is unquestionably a good choice, and it will get you the IIM name, which IMT Ghaziabad lacks. If you are certain that you want to pursue marketing, then disregard IIM Rohtak. When it comes to marketing, IMT G easily outperforms it.
There isn't much of a difference between IIM Rohtak and IMT Ghaziabad, so your decision between them ultimately depends on how you want to shape yourself if your options aren't limited to marketing or if you haven't decided what you'll pursue and explore once you enroll in the B-school. If either of these situations applies to you, then you must make a personal decision.
If you want to study marketing, IMT Ghaziabad is the place to be. If you decide on anything other than marketing, you will end up getting hired for the same corporate positions. IMT G, as a brand, currently offers better prospects than IIM Rohtak and has much more to offer.