Hi,
I checked with several version of ERPNext, last one on 12.10 version. ERPNext have bug in GST report. I am checking GSTR-1 report. I am not find any details inside B2C large customer.
Problem alo have with GSTR-2 report also. It is showing taxable value of IGST(out side state). It is giving tax value 0 for In State (CGST&SGST).