For Preliminary Examination, you need to face two compulsory papers Paper I (General Studies) & Paper II (Aptitude Test).
As you wish to appear in CSE 2015, you should look at General Studies related requirements. You should adopt integrated approach and should commence preparation with Main Examination orientation. This will help in effectively tackling Preliminary Examination Paper I.
For Preliminary Examination Paper II (Aptitude Test), a lot of practice would help you in gaining confidence.
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