Should I join Accenture or IIM Raipur?

Your question basically means whether you should gain experience or pursue MBA from IIM Raipur. In my opinion, joining IIM Raipur is the right choice because

1. You have cleared CAT and got selected. This might never happen in the future again due to the unpredictable nature of CAT. So don’t lose this opportunity.
2. Joining Raipur right now is almost similar to going for a better B school 2 years later as Raipur might be flourishing till then.
3. Even if you work and join IIM Raipur later, your disinterest in the job might be reflected in your interview thus becoming a negative impact on the panelists.

The fear of joining a new IIM is common as one is investing huge amounts of money. But you need to remember that every new IIM becomes an old IIM one day.