Class 12 carries  60%  of the JEE Weightage and class 11 carries 40%. If you are sure that you will be able to solve all the questions in class 12 in jee, then you will be scoring around 216 marks. And almost all the topics covered in 12th require a good grip of the chapters you cover in 11th. Some of the questions are also from a mixture of the concept from class 11 and 12.

You go through each and every chapter important formulas at least once.

In Maths

• conic section 
• sequence and series
• trigonometry

        even complex numbers are  very important topics

In Physics mechanic can be sum up to topic electronic too

In Chemistry class 11 only inorganic and physical part is important

there is nothing much with the organic part.

Use the time available effectively and complete the revision of both 11th and 12th and crack Jee with immense patience and knowledge.

All the Best!:)