Assuming you have the Redmi-note-11R-Convert-Global-ROM.arc file and it passes hash verification (SHA-256 match with official Global light ROM), follow this guide.
The Global ROM has a lower anti-rollback index than your current China ROM. Fix: You cannot downgrade. Find a Global ROM with a matching ARB (Anti-Rollback) version. Use arb_check.exe on the .ARC file before flashing. Redmi-note-11R-Convert-Global-ROM.arc