Well brother clearing JEE advanced is nothing special as there would be around 34k students doing the same. Even I've cracked the JEE advanced paper twice but still I'm studying at NIT.

So I would urge you to focus on getting great rank like under 8k to expect a decent IIT.

Yes it is achievable provided you have one month. There are few tips and books that can certainly boost your score.

1. Practice two JEE advanced paper daily with a clock of 6 hours and two hours break in between.

2. Solve one sample JEE advanced paer daily. I know you might be thinking that my preparation is not upto the mark so I'm ready to solve the papers but this step is inevitable. You have to practice papers.

3. Prepare Inorgainc chemistry very well. Resources JD LEE and NCERT X1 and X11.

4. Prepare for mathematics very well. As there are lot of online help regarding the mathematics like Mr. AA - MNNIT Allahabad etc can prepare your math portion quite well.

Apart from that, solve as much questions as you can from some quality material like AAkash Success magnet or Resonance Exam Booster. These books are really quite helpful in boosting your score provided you you practice from them seriously.

Wishing you all the best..