The comment from the order row are not indexed, to include them in the index you need to create an pre-processor that will enrich the index document with more information. Check how that is done in the accelerator, example CampaignIndexingProviderPreProcessor.
HI Patric,
I added new pre-processor for order row comment. Now am getting correct result while using search service (through code). But in Back office, still no result. Is there any way to get result in BO ?
I think the BO search are searching in the field with name Litium.Foundation.Search.Constants.TagNames.Body, try to add the order row comment into this also.