Microsoft’s SQL Server Management Studio will connect by default to port 1433 and there’s nowhere in the connect dialog to specify a different port from the default. To connect using a different port specify the servername, a comma, and then the port number as shown in this post.
Connect using a different port using a comma
The connection dialog in the SQL Server Management Studio client is shown in the screenshot below. Normally you would just type the server name into field but to specify a different port use a comma then the port number.
The example screenshot above shows "dbname" as the database name and "port" where the port would be. If you wanted to connect to a server named e.g. sqlserver.electrictoolbox.com on port 10443 then set the server name to:
Then specify the login credentials, click the connect button, and assuming everything is correct it should then connect to the SQL Server.