I have 2 another DC with PSC and Virtual center on both site. How I can join my VC in linked mode?
EvgeniyL,
Your question is not clear.
Can you refer to the following document consisting various topology that vCenter supports
Supported and deprecated topologies for VMware vSphere 6.5 (2147672) | VMware KB
and provide us more details on the problem you are having.
Also, you may want to refer to following documentation
1. Enhanced Linked Mode Overview
2. vCenter Server and Platform Services Controller Deployment Types
3. Introduction to vSphere Installation and Setup