How should discover potential bottleneck points which can fatal from performance point of view. If I have JMeter reports and also network stats? Is it possible that I can identify the bottlenecks of the application. If not, what else is required???
This way you will be able to state what maximum number of users can your application under test support, when performance starts degrading and where and when it gonna break.
But if you need to know "why" the application works slowly under the load using only JMeter reports you will be able to identify only networking problems like in How to Analyze the Results of a Load Test indicating high latency or high connect time which might be due to limited capacity or faulty router.
Actually creating and running the load test is not even 50% of the load tester's work, the real fun begins when it comes to results analysis so make sure you have enough information to analyse including (but not limited to)