Hello Mahesh,
I do understand the fact that route and shipping relevant data is available in ECC. But, there is a huge difference between ECC Scheduling Vs gATP Scheduling. While you work with calendars in ECC Scheduling, gATP works based on time streams in which you associate another time stream linked to the calendars. I understand, in ECC the lead time information is stored in tables like TVRO, TVST, T630R and T630L. If you get into your gATP system you will find similar tables there ( /SAPAPO/TVRO, /SAPAPO/TVST.........). So, you need to mirror the ECC data into these gATP tables and setup the condition records accordingly to make it work as expected.
I do understand that this is a bit of pain, but if your RBATP check result should work as expected - then you need to do this. SAP hasn't provided the luxury of CIFing such data from ECC to gATP as they are tagged as Config relevant. Also, please don't forget the fact that there is BOP process in gATP. So, in case of BOP run - the scheduling is completely executed in gATP system and there is no way you could make RFC calls to R/3 system to execute SD scheduling. This is not possible.You may reach out to SAP, but I think they will answer the same.
Hope this helps.
Thanks & Best Regards,
Babu Kilari