bravo! jai_nepal, you nailed the guy right in! now listen here you idiot, if you can't realize how pathetic your own English is, don't tell others to join an insitute. Sorry, my bad; I didn't know that you are still a little kid as your profile picture shows. Seems like you need to learn to put on an underwear before you go to school for some English lessons. Anyways, I'll help you see where you're at regarding English:
- you spelt "please" incorrectly
- only one period after "institute"
- the "h" in "hopefully" should be capitalized
- put a comma after "hopefully"
- remove those two periods after "and"
- "oh" seems redundant since you already used "and"
- put one  space each after "by" and "the"
- remove those two periods after "way" and put a comma instead
- "dont" is incorrect; write either "do not" or "don't"
- replace those three periods after school with a semi colon
Take home message: don't try to be oversmart if you can't help. 

anavon:
pretty much any book available out there will work. but you might learn better from some than from others. if you have access (local book-shop or library at your school), skim through a chapter on books from multiple publishers (like Kaplan, Barron, etc); buy the one that suits you the best. 10 months is more than enough to prepare for GRE. if you are motivated enough to study regularly on your own without slacking off, there's no need to join an institute. you might get a little more help from an institute, but you can find answers to things you don't understand on the internet.