Indian Engineering Services (IES) exam examination comprises a written test followed by a personal interview. Following are some tips which will help you cracking the examination:

Be aware of what is happening in the country and across the world
Read newspapers and watch the news on TV regularly
Refer to as many latest GK books as possible
Try to refer to past question papers and solve as many questions as possible
Make a routine and stick to it.
Try to take a few mock tests, if possible. They help a lot in preparing you for the main exam
Be very logical when you are replying to questions.