Do engineering background students get more preference than that of just graduation to get enrolled in top colleges? E.g: IIM.

That is an absolute myth. It is not anyone's fault if they think otherwise because the maximum candidates appearing for these exams have an engineering background (which is again an "Indian" thing). IIMs give weightage to your percentage and college (of any field) if you are a fresher and for exper

This is not true that the engineering background students get more preference to get enrolled in top colleges like, IIM's prefer to take both engineers and non-engineers to bring diversity in the class. They bring a different perspective altogether to class discussions.

In IIMs, Engineering graduates do not have any preference but if you are from a Arts or commerce stream such as B.Com, B.Sc, B.A, etc. then definitely you are going to get some extra weight-age at the time of final Interview.