Hello Naveen,
For BP replication between CRM and ECC, you should follow the steps below to perform the settings in your system:
1. Make sure the middleware settings are correct. Please refer to this SCN blog.
General Middleware settings for Data Exchange
2. Make sure the BP number range mapping are consistent between CRM and ECC.
customizing path:
SPRO-> Cross-Application Components-> SAP Business Partner-> Business Partner-> Basic Settings-> Number Ranges and Groupings
3. In table COM_BUPA_CALL_FU of ECC system, the function modules below for event R3OBI are activate.
R3OBI BUPA 2000000 COM_BUPA_MAIN_BP_INBOUND
R3OBI BUPR 2000000 COM_BUPA_REL_BP_INBOUND
Hope my answer helps.
Best regards,
Julin Xin