Dear Shivudu,

JEE Main is one of the competitive level exam.

260 is a very good score in JEE Main in order to acheive your aim you need to be dedicated and self motivated. 

First, you need to get good hold on your subjects. Take help of NCERT books it will help you to make your concepts clear and to build your fundamentals strong. 

Give extra attention to the topics which holds more weightage in the exam.

Apart, from NCERT books you can go through HC Verma for physics, OP Tandon for Chemistry and RD Sharma for Mathematics. 

Refer previous year papers to know the exam pattern and to know the level of the questions asked in the exam. 

To score good marks you need to do lot of practice Speed and time management is very important in JEE Main. It tests your pressure handling skills and how quick you can think so you should solve as many as mock test series for your practice.

All the best for your preparation and exam!!