Hi Dipak,
If this is in TM, then post it in SAP TM forum.
If it is SAP EM, then go to IMG -> Event Management -> Event Messages, Status Queries, and Web Interface -> Define Criteria for Event Message Processing -> Time Zone Assignment.
You can config and customize to call custom function module in above to report events in vendor /supplier time zone.
SAP EM FM:
/SAPTRX/CHECK_DATETIME
/SAPTRX/CHECK_TIME
/SAPTRX/CHECK_TIMESTAMP
/SAPTRX/CHECK_TIMEZONE
/SAPTRX/CONVERT_DATE_TIME
Regards
GGOPII