Create an initial Execute SQL Task in the Control Flow and use the following code in it (you could change to a LIKE statement or paste your exact system expectations in place of the SQL 2014 output I have here):
IF ((SELECT @@VERSION) = 'Microsoft SQL Server 2014 - 12.0.4213.0 (X64)
Jun 9 2015 12:06:16
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Enterprise Edition: Core-based Licensing (64-bit) on Windows NT 6.3 <X64> (Build 9600: ) (Hypervisor)
')
BEGIN
SELECT 'TRUE' As Result
END
ELSE
SELECT 'FALSE' As Result
You can of course do several things with this, one of the easiest and clearest for SSIS developers would be to store the results in a SSIS variable and assign the Precedent Constraint after the SQL Task to Expression and Constraint.
If the Execute SQL Task Succeeds and returns TRUE it will allow the rest of the execution, which could be a single package, part of a larger execution stream, or a master package. If it fails or returns FALSE your package stops... might be worth putting in another path for an alert message or log of this though.
You can modify the IF check for different possibilities:
IF ((SELECT @@VERSION) LIKE 'Microsoft SQL Server 2014%'
Or as @billinkc suggests and you were headed originally:
IF ((SELECT CAST(SERVERPROPERTY('ProductVersion') as CHAR(2))) = 11)