Not all the coaches have SM berth some coaches are ICF Rajdhani coach and some have GR Coach but have RAC...
I get G6 23 Seat which is SMB showing on IRI but coach was Old ICF Rajdhani coach so 23 is Side Lower...
So there is always tragedy changes in seats both up and down train journey due to IRCTC and Coach info not correct updated..
So...
more... it all depend upon u that which seat u will get...