BIT Sindri is far better than IEM in every aspect be it in campus, faculty, or placement, etc. Discussed below are a few of the reasons why. 

Placements: (Winning Institution - BIT Sindri)

• In BIT you will get placed in core companies. 
• While in IEM, mass placement is done in IT companies and TCS, Infosys are major recruiters. 

Type of Institution: 

BIT Sindri is a Govt. institution and ought to be better than IEM which is private.

Both IEM and BIT have their own reputation. Here is given the table differentiating both the institutes.

In terms of education, Birsa Institute of Technology or BIT Sindri is a good option. It also gives students a friendly environment for study and great exposure. So if you are looking for enrolling in BIT Sindri, then go ahead with it.