am very poor in maths but i want seat in advance what can i do am very depressed about it

Mathematics is one of the easiest subjects if you understand the basics. So for now, try to focus on the basic and make concept strong. Being one of the toughest exams, one needs a lot if hard work and determination to get good score in Jee Advanced. First you should go through the entire syllabus. Instead of choosing a random topic from the syllabus, you must break your preparation into sections. Sub-topics from each section should be selected and then strategy on clearing concepts must be made. Never leave any concepts doubtful or unsolved.

To do the best, you need the best books for preparation of Mathematics-

• Mathematics

Maths, RD Sharma
Complete mathematics for JEE advance by TMH
New pattern mathematics for JEE advanced by Arihant publications

Make a proper routine. During last days, focus more on the important chapters. When done with the syllabus, give mock tests regularly, and solve previous year papers also. Time management is one more important thing you should look upon.
Here I'm attaching the link of previous year question papers of Jee Advanced. Solving these papers will help you a lot to understand the exam pattern and what type of questions are actually asked. http://engineering.careers360.com/articles/jee-advanced-question-papers