I have started using cocos2dx on linux.
On mac Xcode is there and on Windows Visual Studio is there.
But which editor should I use here?
I need the feature of auto complete and where I get the suggestion of methods that can be used.
Like by pressing ctrl+space gives suggestions.
There are a lot of editors to choose from.
The most popular with your requested features and tons more are:
Vim http://www.vim.org
Emacs https://www.gnu.org/software/emacs/
Code::Blocks http://www.codeblocks.org
Can I also use Android Studio for the editing. Will I be getting suggestions there also.
I have been used Android Version 1.3 but was not getting any suggestions there.
I am not sure about the higher versions.
Will I be getting suggestions in Android Studio?
You can using netbeans too. But I recomended codeblocks.
Using following command for generating codeblocks project.
cmake -DCMAKE_BUILD_TYPE=Debug …/ -G “CodeBlocks - Unix Makefiles”
This thread for using codeblocks link.
I strong recomend QTCreator.
Is really easy to setup a cocos2d project and have nice feactures 
All you need do is open a CMakeLists.txt file like a project and is ready to go.
Yes. It’s just based on IntelliJ.
If you have problems with code completion, you can watch the video for a solution:
Can You explain this process in bit more detail.
I really want a good editor for cocos2d-x on linux.
But everything here is so complicated and if I get a editor which is easy to make that will be so relaxing.
Please tell me the steps in detail.
in this link they show step by step.
http://www.cocos2d-x.org/wiki/User_Tutorial-How_to_open_cocos2d-x_project_into_Qt_Creator_IDE