Hi Narayan. Even when a core field (such as StatusEquatesWith) is not listed among the fields available in the Grouping tab of a report, I've had some success switching the Grouping to Text Mode, "taking a shot" at what I'd expect would be the target field in question, and then (Hallelujah!) charting it. So I suggest you give it a try...but be ready to punt and use the calculated field, otherwise, which will certainly work.
Regards,
Doug