Some of my friends attended Marwari College and according to their experience, it is average at best. Classes remain suspended most of the time. The infrastructure is not that good. The management is not proper. The faculty base is not that great, you will have to study on your own. If you have other better options go for it.
St. Xavier’s College is an autonomous university. Classes and examinations are held regularly at the university. There is also a mandatory 75% attendance rule that you need to follow. If you want to take admission in B.Com (Hons), you need to have Mathematics in your 10+2. However, since it is a private college, the course fee is higher.
Marwari College is a Govt. college. The classes are held regularly. They also have a 75% attendance rule, but it can be adjusted. Sometimes examinations get delayed.
You can choose either of these two institutes according to your convenience.