Hello aspirant,

NO dear, you'll not face any issues related to redoing class 11th again. You can give your JEE mains examination only on the year of passing of your class 12th examination.

Further, every candidate is eligible to give JEE mains exam 3 times and JEE advance 2 times consecutively, from the year of passing the class 12th.

Further, below I am sharing some of the best preparation tips and strategies thta you must follow in order to crack JEE mains in first attempt :

Prepare A Well-laid Plan

Draft a daily schedule.

Prioritize the topics that require more time and relevant to the subject.

Stick to the routine and pay special attention to problems.

Get Hold Of The Syllabus

Manage your time effectively

Understand Basic Concepts

Before delving into JEE preparations, know the JEE syllabus and understand the basic concepts present in the syllabus.

Evaluate your knowledge on basic concepts.

Make notes on required topics.

Choose The Right Study Material

Further, to know further details and preparation for JEE mains exam follow the below mentioned link :

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

further, below are some of the best books that you must follow for your JEE mains preparation ;

For PHYSICS :

Concepts of physics for JEE - H.C. Verma (Vol. I and Vol. II)

Fundamentals of Physics by Halliday, Resnick & walker

Understanding Physics by D C Pandey (Arihant Publications): Set of books for

Electricity & Magnetism

Mechanics (Vol. 1 & 2)

Optics & Modern Physics

Waves & Thermodynamics

Problems in General Physics by I.E Irodov

Understanding physics by Freedman and Young

Problems in physics by SS Krotov

Problems and solution of physics by Shashi bhushan tiwari

FOR CHEMISTRY :

NCERT Textbooks (for Class XI and XII )

Modern Approach to Chemical Calculations by R.C. Mukherjee

Organic Chemistry by O P Tandon

Concept of Physical Chemistry by P Bahadur

Concise Inorganic Chemistry by J D Lee

Physical Chemistry by P.W. Atkins

Organic Chemistry by Morrison & Boyd

FOR MATHEMATICS :

Objective Mathematics by R D Sharma

Plane Trigonometry by S L Loney

The Elements Of Coordinate Geometry by S L Loney

Algebra by Dr S K Goyal Arihant Publications

Play with Graphs by Amit M Agarwal (Arihant Publications)

Differential Calculus by Amit M Agarwal (Arihant Publications)

Integral Calculus by Amit M Agarwal (Arihant Publications)

Complete mathematics for JEE Main TMH

Further, to know more about the JEE mains preparation books, you can follow below mentioned link :

https://engineering.careers360.com/articles/jee-main-preparation-tips

I hope that this will help.