I want to find free apps/websites where I can collect my ideas thought
In the form of flow chart, notes etc
Which can be interconnected/linked for better understanding
& also put images links etc
To manage myself
Like mural.ly ,MindMap,Evernote

For what platform? PC, Android, IOS, Blackberry?

For both PC & Android which can b used online/offline

You can try
Blumind (http://blumind.org/)
XMind: Professional & Powerful Mind Mapping Software (http://www.xmind.net/)
List of concept- and mind-mapping software - Wikipedia, the free encyclopedia (http://en.wikipedia.org/wiki/List_of_concept-_and_mind-mapping_software)

For Android:
The top five mind mapping apps for the Android tablet - TechRepublic (http://www.techrepublic.com/blog/tablets-in-the-enterprise/the-top-five-mind-mapping-apps-for-the-android-tablet/)