Implement NSFetchedResultsControllerDelegate for UICollectionViewController. Refered this : http://samwize.com/2014/07/07/implementing-nsfetchedresultscontroller-for-uicollectionview/

CollectionViewControllerExtension_NSFetchedResultsControllerDelegate.swift

class CollectionViewController: UICollectionViewController {
    
    var sectionChanges: [[NSFetchedResultsChangeType: Int]]? = nil
    var itemChanges: [[NSFetchedResultsChangeType: AnyObject]]? = nil
    
    ...
    
}

// MARK: NSFetchedResultsControllerDelegate
extension CollectionViewController: NSFetchedResultsControllerDelegate {
    func controllerWillChangeContent(controller: NSFetchedResultsController) {
        sectionChanges = [[NSFetchedResultsChangeType: Int]]()
        itemChanges = [[NSFetchedResultsChangeType: AnyObject]]()
    }
    
    func controller(controller: NSFetchedResultsController, didChangeSection sectionInfo: NSFetchedResultsSectionInfo, atIndex sectionIndex: Int, forChangeType type: NSFetchedResultsChangeType) {
        sectionChanges?.append([type: sectionIndex])
    }
    
    func controller(controller: NSFetchedResultsController, didChangeObject anObject: AnyObject, atIndexPath indexPath: NSIndexPath?, forChangeType type: NSFetchedResultsChangeType, newIndexPath: NSIndexPath?) {
        switch type {
        case NSFetchedResultsChangeType.Insert:
            itemChanges?.append([type: newIndexPath!])
        case NSFetchedResultsChangeType.Delete, NSFetchedResultsChangeType.Update:
            itemChanges?.append([type: indexPath!])
        case NSFetchedResultsChangeType.Move:
            itemChanges?.append([type: [indexPath!, newIndexPath!]])
        }
    }
    
    func controllerDidChangeContent(controller: NSFetchedResultsController) {
        collectionView?.performBatchUpdates({ () in
            for dic in self.sectionChanges! {
                for (type, sectionIndex) in dic {
                    switch type {
                    case NSFetchedResultsChangeType.Insert:
                        self.collectionView?.insertSections(NSIndexSet(index: sectionIndex))
                    case NSFetchedResultsChangeType.Delete:
                        self.collectionView?.deleteSections(NSIndexSet(index: sectionIndex))
                    default:
                        break
                    }
                }
            }
            
            for dic in self.itemChanges! {
                for (type, item) in dic {
                    switch type {
                    case NSFetchedResultsChangeType.Insert:
                        self.collectionView?.insertItemsAtIndexPaths([item])
                    case NSFetchedResultsChangeType.Delete:
                        self.collectionView?.deleteItemsAtIndexPaths([item])
                    case NSFetchedResultsChangeType.Update:
                        self.collectionView?.reloadItemsAtIndexPaths([item])
                    case NSFetchedResultsChangeType.Move:
                        let items = item as [NSIndexPath]
                        self.collectionView?.moveItemAtIndexPath(items[0], toIndexPath: items[1])
                    default:
                        break
                    }
                }
            }
        }, completion: {(finished) -> Void in
            self.sectionChanges = nil
            self.itemChanges = nil
        })
        
    }
}