These three colleges are reputed institutions in India. When we are comparing these three, the best option would be IIT Mandi, it has many distinctive features that other institutes lack.
If you secure a seat in EE at IIT Mandi, you will get eminent support from renowned scholars for your research and higher studies. The EE branch also provides grand placement support to the students.
The electrical branch of IIT Dhanbad is really weak. When it comes to the ME or CE branch at Mandi, the scholars will help you reach out to foreign universities for your higher studies, but the placement support is comparatively low in this branch. So IIT Dhanbad is better for the ME or CE branch. If you are interested in the fields of biotechnology or engineering physics, IIT Mandi does not have good faculty support.
So, you can select IIT Mandi if you are interested in the CSE field, the EE field, the best campus life, or the branch-changing policy.