Hello
For running an application that supports multi-paring the most recommended is the Wireless UART example that we provide in the SDK. However for each application we test a number of connections supported without memory or related issues, this will be different in each application. We can see the maximum connections for each application in source/app_preinclude.h --> gAppMaxConnections_c (Wireless_uart_freertos for example support 8 in the SDK example)
For complementary information about Multiple Connections in BLE please refer to Chapter 9.10[Bluetooth Low Energy Application Developer’s Guide].
Best Regards
Luis