Hello Rohini

MAH CET exam has been a test of speed. If you are starting your preparation, firstly, you should know the detailed syllabus and pattern of the exam. 
Know about your strong and weaker areas and work on to improve the weaker section. 
You should practice previous year question papers and mock tests. It will help you a lot. Along with speed, accuracy is also the key factor to perform well in the exam. So, you need to improve your speed as well as accuracy. And a lot of practice is required to build up speed. Remember, the more you practice the better you do in the exam. It is possible to crack the exam. Just hard work, dedication, practice is required.

Good Luck!

I don't think it makes a big difference whether you are taking the CET exam for the first time or the fifth time. Chances of you making it to JBIMS depends on the level of your preparation and how effectively you are able to use your 2.5 hrs of the exam.CET is an easy exam as compared to CAT and may require a lesser time to prepare. I had a student who had joined me just 45 days before the exam without having prepared for any aptitude exam like CAT before. He managed to get a top 10 rank and make it to JBIMS.