Senthilkumar,
I would review / study your weak areas based on the questions you are missing on the simulated exams. Don't forget to review the questions you got correct as well. There were often times on the simulated exams that I would have to guess and sometimes guessed correctly but it is important to go through those questions as well to be sure you understand why you made the correct choice. If you haven't already, take a look at some of the other recent lessons learned posted on the forum which also list other mock exam questions you can try. Keep working at it. You will improve as you continue to work through more questions and study the materials.
Mark