Revision of JEE MAIN syllabus is made after all mock tests or before

I would suggest you to do the revision after completing One Chapter as it will help you to build it strongly & give the mock test to analyze your preparation. Here are some preparation tips which you can follow.

Build and Focus on your strengths
Check your short Notes & Revise the important formulae:
Don't go on doing Mock Tests
Dont let self -doubt creep in
Gets sufficient practice and revision
Try to solve at least 70-80 numerical every day.
Do read, errors and measurement, environmental chemistry, and sets, relations.
Read the questions first and mark which would do first. This will definitely avoid wastage of time on other questions.

Careers360 has come up with JEE Achievers Preparation package which includes unlimited tests, online 24*7 expert chat facility system, conceptual e-lectures and many more plus points for you. It has a time table feature as per which you will have to choose the exam date and your complete time table will be auto-created as per what topic you should focus on and the amount of time to be given on each topic.

Apart from the above mentioned:The best part is-

In respect to the program mentioned, you can practice the tests any time of the day and that too unlimited, so utilize it to the extent.
There are concept wise lectures, which means you can get your minimal to important concepts cleared and followed with it can give the test and analyse your performance.
Even if you plan to study at 3am, and you face any query, you have online doubt facility system where the experts will help you asap and you don't have to wait till next day.

Further to know more benefits helpful for you, you can check details and proceed from here- https://goo.gl/zTUHWw

Good Luck!