Please suggest me some preparation tips for IIT JEE examination in 11 months duration ?

Indian institute of technology colleges offer admission in B tech course through Joint entrance examination..

You have to start preparation as soon as possible. You must know complete syllabus and exam pattern for IIT JEE exam . Always start preparing from 'Basics'. Try to learn the fundamentals of the concepts rather then memorizing the concepts. than you have to make important notes for high weight age topics and revised them regularly. Always try to solve 50-60 problems on per topic or chapter.

For better preparation you have to solve the previous year question paper of IIT Joint entrance examination or you can buy books for it

Best books :
Physics ::
NCERT Physics for Class XI and XII (good introduction)
Physics by D.C. Pandey, Arihant Publications
Fundamentals of Physics, by Halliday, Resnik and Walker (Optional)
Concepts of Physics, Vol.-I & II, by HC Verma
Problems in Physics by IE Irodov

Chemistry:
NCERT Chemistry text books of class XI and class XII
Organic Chemistry by Morrison and Boyd
Physical Chemistry by RC Mukherjee
Physical Chemistry by P Bahadur (good for any Engineering entrance exam)
Arihant Organic Chemistry Objective (Optional)
Organic, Physical and Inorganic Chemistry books by OP Tandon
For numerical problems-P Bahadur
Inorganic Chemistry by JD Lee

Mathematics:
NCERT class XI and class XII books (all students should start with these early)
For best concepts you can purchase ‘IIT Mathematics’ by ML Khanna
New Pattern IITJEE Mathematics of Arihant Publications by Dr SK Goyal
Books by SL Loney (Good for coordinate Geometry and Trigonometry)
Tata McGraw Hill (TMH) books
GN Bernnam – only use it for calculus as other sections are too advanced for JEE