gujarat board examination of 4h semester ends on 23rd of March and so have only 10 days for preparation of jee so how to prepare

You should focus on quality preparation. Focus on the topics which carries more weight age in the exam.

Chemistry:

Physical

Mole concept, Thermodynamics, Equilibrium and Electrochemistry, Practice sufficient number of numerical as they form a major portion of questions.

Organic

Stereochemistry, GOC (General Organic Chemistry), Reaction mechanism and Functional Group Analysis.

Inorganic

Mainly conceptual questions, concerned with structures, processes and applications, Chemical Bonding, Coordination Chemistry & Qualitative Inorganic Analysis.

Physics:

Mechanics
Electricity and Magnetism
Modern Physics
Optics
Heat and Thermodynamics and Waves and Sound
Measurement and errors

Maths:

Vectors & 3D
Complex Numbers
Definite Integral
Conics and Trigonometry
Differential Calculus
Permutations and Combinations
Matrices & Determinants

You should also solve previous year papers to get a idea about exam pattern and level of questions. Try to solve as many as MCQs and complete mock test series to analyze your preparation level and to know your strength and weakness.

You can also check below article to know about topic wise weight age in the exam-

http://www.engineering.careers360.com/articles/jee-main-2015-important-topics-books-know-from-experts