Based on analysis of previous years papers, there are few topics which carry more weightage for every subject in JEE Mains. In Mathematics, Co-ordinate Geometry gets 5 questions. Limits, Continuity and Differentiability, Integral Calculus get 3 questions slot each. The rest get 2 and 1 questions slot. For complete breakdown, please read our article: https://engineering.careers360.com/articles/jee-main-syllabus-weightage . So if you can prepare accordingly, you can score good. Divide the syllabus into Class 11 and Class 12 and the topics as "Need to Learn", "Weak" and "Strong". And then because you hardly have a month's time while preparing on the weaker topics also have a strong foundation on the topics that you are good at. These books can help you:

Objective Mathematics by RD Sharma

Plane Trigonometry by SL Loney

The Elements of Coordinate Geometry by SL Loney

Algebra by Dr. SK Goyal Arihant Publications

Play with Graphs by Amit M Agarwal

Differential Calculus by Amit M Agarwal

Integral Calculus by Amit M Agarwal

Integral Calculus by Amit M Agarwal

Complete Mathematics for JEE Main TMH

JEE Knock out package can help you score good in JEE Mains. https://learn.careers360.com/knockout-jee-main-april/ .