Hi Roy,

To get more than 230 marks in jee main is not hard but it's not easy also.so for that first of all clear your basic concepts of the chapters you are intersted.

and then try to solve previous year question paper in a time frame so it will boost up your preparation.

Thanks 

the biggest challenge lies in the fact how you manage your board exams and jee entrance exam simultaneously. well after that it involves a lot of studies and hard as well as smart work. NCERT is the best source to start your preparation as it brushes up your basics and fundamental details for all the three subjects.

after enabling your basics you can revert to a step ahead by consulting books like that of 

H C Verma (physics)

Resnick Halliday (physics)

O.P Tandon(chemistry)

R C Mukherjee (chemistry)

RD Sharma (mathematics)

Arihant publication as it is available for specific chapters in mathematics which is essential for mathematics.

you must solve the previous year questions very thoroughly and also you must solve mock paper on a daily basis.

please join an online test series for testing your level of preparation it can be of any coaching institute.

all the best !!!!!!!!!!!!!!!