IIM Indore has recently been criticized for increasing the number of students in each group. For now, the new location might be risky. Since IIM Ranchi is a growing IIM, I will suggest it. Alternate schools will always have a second chance at things; this is how things usually work everywhere. Also, the quality of the teachers can't be matched 100% by IIM Indore's main campus. Even if the staff stays the same, Mumbai won't be able to copy the culture of the I campus right away.
IIM Indore has more than 600 students in each class, which is almost 2.5 times as many as IIM Ranchi. The point is to study with a group of 600 or more people instead of 240. I say go for Ranchi.