Hi Vishnu,
If the SC fails to replicate to the backend as a PR in the backend system you can first check the reason why the SC was not replicated by using the t-code BBP_PD or through RZ20.
Incase everything is in order and it has to be replicated you can check the report CLEAN_REQREQ_UP or you can use certain other reports such as BBP_PD_SC_TRANSFER
Regards
Pramod