Hi Sankar,
First of all, it is technically possible to connect two CRM systems directly. We need to use IDoc to connect two systems. Julin have provided the link of document "External Interface (XIF) Setup".
Just one more information, if you've already connected CRM1--ERP--CRM2, It is not supported in the standard system to connect CRM1 and CRM2. If you still need to connect CRM1 and CRM2, please set your filters carefully to stop loop replicating of master data.
Also please check following note.
1143540 - Consulting: Information about Multiple CRM
BR
Dean Yan