For RC preparation, it is important to read as much as possible and from as many sources as possible. You have to read widely and deeply. Once you read an article, make it a point of summarizing the article in a few sentences. This will improve your comprehension skills.
Check out a few RC practice tests here:
The preparation for NMAT is not very different from the preparation for CAT, since they have a lot in common. So, you can follow a similar approach. However, once the exam gets closer, you'll have to take a few NMAT mocks to fine-tune your test-taking strategy.
Check out a few previous years CAT papers here:
I would strongly advise you to focus on doing well in CAT 2016 and not worry about reservations. India has some excellent MBA institutions like IIMs, ISB, XLRI, FMS etc. Start preparing well by solving previous years papers of CAT and taking Mock tests.
The best way to prepare for Vocab is by finding out the meanings of words as and when you find new words and trying to use them when you speak/write. It is not a very good idea to prepare for Vocab by trying to study words from word lists.
As far as CAT is concerned, if you are just starting your preparation, try solving a few papers from previous years. This will give you an understanding of which topics you are weak at and which topics you are strong at and you can stategize your preparation accordingly.
Cracku has more than 150 topic tests from previous CAT papers. You can find them here: