I have started my preparation in the month of September what should be my strategy to secure more than 95 percentile in cat exam

You can definitely give 2017 a try,but honestly you have very limited time for Preparation, my personal recommendation is to attempt 2018 whole heartedly with full preparation. As of Now just brush up basics and give some 3-5 odd mock exams before CAT 2017. Also, you can give onljne mock tests on platforms like HitbullsEye, Oliveboard, TestFunda. If you score good enough, then its the best case. Incase you don't,you should aim for 2018 with 99percentile. Now, There are plethora of books available but byfar the best have been mentioned below. 1.How to prepare for Quantitative Aptitude for the CAT by Arun Sharma. 2.Pearson Guide to Quantitative Aptitude for CAT by Nishit Sinha. Moreover, recommended to go through TIME Coaching Institute Material for Logical Reasoning , Verbal Ability, Data Interpretation of solved examples and last 5year question sets for Quantitative aptitude. For Easy level problems, or for beginner level preparation you should go with Chandresh Agarwal and notes from CATKing Coaching classes where there is elaborate pattern.

It's a bit late but not too late. Firstly try to get a hold of all the topics in quant. Then start giving mock tests. Give as many as you can as it will help you get better. You will be able to manage your time better and get to know where you need to work upon. Subscribe to online websites like testfunda, oliveboard etc where a lot of people give tests as it will help you get an idea of where you stand.

You will have to analyse each test you give and know where you need to work upon. Practice makes one perfect and this is absolutely true in this case.

September is half past. There are about 70 days to the actual exam. You need to focus in a right manner at following areas:
-Complete the quant topics by 15th October
-Complete enough RCs by 20th October
-Get a good hold of various DILR questions by November starting.

-Finally, and most importantly, start giving mock tests right away without any further ado. Also, take up sectional tests at least once a week now, and at least twice a week from November.