No problem with RestKit adding to the project. Still not sure. How to solve the problem.
Followed below steps to overcome the issue:
1. Deleted the old view and associated view controllers.
2. Created new view, New controller. Be careful with connections and remove it before deleting any associated views.
3. Hurray the got instances of carousels worked.
But above seemed like a work around but still didn't figure out the issue.