I would say that your preparation for Jee can't be done now. Seeing the marks that you are getting in MAINS I would say you have very little chance to make it through JEE ADV. Qualifying in JEE MAINS should not matter now as it would be stupedity to prepare for JEE ADV.now.But still if you want to try to give JEE ADV. I would suggest you some things I would do if I had to prepare from now:

• For inorganic:
• Go through the chemistry ncert book(both 12 and 11) thoroughly and study the key concepts and reactions as in the past, many straight forward questions or those based on understanding of reactions have been asked.
• For periodic table, I would suggest you to have a thorough knowledge of all the properties.
• For s and p block, you should know the reactions and properties of elements really well.
• For d block have basic knowledge of the properties and special properties or exceptions given in ncert of elements which are very common.
• Also you should know about the structures of compounds as potassium permanganate and potassium dichromate etc.
• For physical: The 12th ones are always a bit easy and there is a question based on equivalency concept almost every year.
• For organic : The questions come simply on deep understanding of topic and reactions.
• The basic reactions (Tollen's, Formation of aldehyde and others etc) must be on your finger tips. When given a series of reactions you should be able to identify some step and guess the other products using it.
• Nomenclature is pretty simple.
• Isomerism :You should have a good command over both structural and stereoisomerism especially when it comes to determining total no. of possible isomers or identifying the correct product in reactions of stereo-specific type.
• For physics:
• You would know the basics of all topics(11 and 12), that's what I'm supposing.
• Questions from 12th are mostly easy, though those from nuclear physics are a bit tricky, yet simple if you know the basic concepts thoroughly.
• For maths:
• I would suggest you to search for formulas of straight line, circle and conic section as when you have crammed them up questions really become easy and quick to solve.
• You should be able to visualize 3-d geometry to solve questions on it.
• Questions on matrix and determinant are easy to solve if you know their formulas given in ncert.
• Trigonometry should be at your tips as it its used in most of the questions.
• Questions on sequence and series are pattern seeking ones and once you find the pattern they are rather easy to solve, provided you know how to solve A.G.P. and other special series.
• Properties and methods to solve for functions should be known.
• Binomial and other concepts are basics. You should know about the expansions and binomial coefficients.

Also I would recommend you to see one of the last year's papers and find out for yourself, in what areas you do lag and work on them accordingly.