How load balancer will behave when websocket connection will start? It will redirect directly to server or will open persisted connection through load balancer and stay there? Have load balancer limit of opened connections?
WebSocket connections are opened through the Render proxy, which sits in front of your service. They are not made directly to the service. Regarding connection limits, the Render platform does have internal limits to ensure quality of service, but this is generally not something a user should bump up against.