Dear candidate

The Integrated materials and objective books provided by the Sri Chaitanya college have a lot Information that a student requires and those will be more than enough and you don't need to buy other books otherwise they will be wasted and  buy other reference books only if you need otherwise they will be wasted and i recommend you to complete studying your integrated materials and only then buy other reference books for extra information then only you will be able to make proper use of them otherwise they are of no use

Visit the below mentioned link to know few preparation tips, weightage of the topics ,exam pattren, and if you still wish to buy best reference books for preparation for JEE Mains have a look at it

https://engineering.careers360.com/articles/how-prepare-for-jee-main

Hope this Information is helpful