Hi Chaitanya,
if you use RA repair order type, then service material is not required to use and hence IRRS item category will not trigger
can you ensure whether you need repair order with service material or without ?
If you need service material at which all your cost should be posted then use repair order RAS or else use RA
and in your scenario, is IRRS item category points to service material or customer material?
if possible, put screenshot for further analysis
thanks
santosh